Enzymatic Mechanisms and Structural Insights into Histidine Biosynthesis in Corynebacterium glutamicum
The enzymatic machinery of L-histidine biosynthesis in Corynebacterium glutamicum is characterized by high catalytic efficiency, precise substrate specificity, and complex allosteric regulation. Each of the ten enzymatic steps is mediated by a dedicated enzyme or multifunctional protein, many of which exhibit unique structural features that distinguish them from their homologues in other organisms. This review provides a detailed analysis of the catalytic mechanisms, kinetic parameters, and three-dimensional structures of key enzymes, with particular emphasis on ATP phosphoribosyltransferase (HisG), imidazoleglycerol-phosphate synthase (HisFH), and histidinol-phosphate phosphatase (HisN).
ATP phosphoribosyltransferase (HisG) catalyzes the first committed step: the condensation of ATP and phosphoribosyl pyrophosphate (PRPP) to form phosphoribosyl-ATP (PR-ATP) and pyrophosphate (PPi). HisGCg belongs to the long form of ATP-PRTs, consisting of 281 amino acids, and functions as a monomer in solution. It adopts an L-shaped architecture composed of three distinct domains: two catalytic domains forming the active site cleft, and a regulatory domain capable of binding L-histidine. The active site lies at the interface between the first two domains, where PRPP and ATP bind cooperatively. Kinetic analysis reveals a specific activity of 2.19 ± 0.09 mmol·min⁻¹·mg⁻¹, a Km for PRPP of 0.08 ± 0.01 mM, and a Km for ATP of 0.22 ± 0.02 mM. The kcat value is 1.91 ± 0.14 s⁻¹, indicating moderate turnover. Notably, HisGCg exhibits non-competitive inhibition by L-histidine with a Ki of 0.11 ± 0.02 mM, consistent with feedback control.
Structural modeling based on the crystal structure of Mycobacterium tuberculosis HisGMt (62% sequence identity) predicts a nearly identical fold for HisGCg. The regulatory domain binds histidine through interactions with residues Gln215, Leu231, Thr235, Met250, and Ala270. Mutation studies confirm these residues are critical for feedback inhibition: a triple mutant (N215K/L231F/T235A) displays significantly reduced sensitivity to histidine (Ki = 4.15 ± 0.21 mM) while retaining full catalytic activity. This makes HisG an ideal target for engineering histidine-overproducing strains. Furthermore, gel filtration experiments show that HisGCg exists in equilibrium between dimeric (active) and hexameric (inactive) forms. Histidine promotes hexamer formation, which can be reversed by excess PRPP, suggesting a dynamic allosteric switch.
Imidazoleglycerol-phosphate synthase (HisFH) performs the fifth step: the conversion of PRFAR to imidazole-glycerol phosphate (IGP) and 1-(5-phosphoribosyl)-5-amino-4-imidazolecarboxamide (AICAR). In E. coli and S. typhimurium, this reaction requires a heterodimeric complex of HisF (synthase subunit) and HisH (glutaminase subunit), which channels ammonia from glutamine directly into the active site. However, in C. glutamicum, deletion of hisH does not impair growth, suggesting functional redundancy or alternative mechanisms. Biochemical evidence indicates that HisFCg alone can catalyze the reaction under physiological conditions, likely via ammonia-dependent substrate amination. This phenomenon may be attributed to the ability of HisFCg to utilize ambient NH₃ when glutamine is unavailable, a feature absent in other species.
Structurally, HisFCg shares significant similarity with HisFEc but lacks the N-terminal glutaminase domain.Tiropramide MedChemExpress Despite this, it retains the ability to complement both hisF and hisH deletions in E.Butylphthalide Protocol coli, confirming its catalytic versatility. The absence of a glutamine amidotransferase activity suggests that HisFCg evolved a novel mechanism to bypass the need for HisH. This finding has profound implications for industrial applications, as it allows histidine production independent of glutamine metabolism—a major metabolic burden.
Histidinol-phosphate phosphatase (HisN) catalyzes the dephosphorylation of L-histidinol phosphate (Hol-P) to yield L-histidinol.PMID:35216324 In C. glutamicum, this activity is encoded by hisN, a gene previously unidentified due to lack of sequence homology to known phosphatases. HisNCg belongs to a new class of phosphatases unrelated to either the DDDD-superfamily or PHP-superfamily. Instead, it clusters within bacterial-like inositol monophosphatases (IMPase), sharing high sequence similarity with proteins from high-GC Gram-positive bacteria. Four homologues exist in the genome (cg0911, cg2090, cg2298, cg0967), all containing conserved IMPase domains.
Deletion of hisN results in partial auxotrophy, indicating functional redundancy among the four homologues. One of them likely compensates for the loss of HisN activity, possibly through overlapping substrate specificity. Unlike bifunctional Hol-P phosphatases found in E. coli and S. typhimurium, HisN operates independently, allowing for modular regulation. This separation may facilitate fine-tuning of pathway flux without affecting earlier steps.
The final two steps are catalyzed by a single enzyme: histidinol dehydrogenase (HisD). It oxidizes L-histidinol to L-histidinal, then further oxidizes it to L-histidine, consuming two molecules of NAD⁺. HisDCg acts as a homodimer, with each subunit contributing to the active site. The enzyme is metal-dependent, likely requiring Zn²⁺ or Mn²⁺. Structural modeling based on E. coli HisD shows a similar dimeric arrangement, with active sites located at the subunit interface. Residues from both subunits coordinate the substrate and metal ion, while NAD⁺ binds to one subunit only. A Bi-Uni Uni-Bi ping-pong mechanism is proposed: L-histidinol binds first, followed by NAD⁺; NADH+H⁺ is released while L-histidinal remains bound; then a second NAD⁺ binds and is reduced, releasing another NADH+H⁺ and yielding L-histidine.
Kinetic analysis confirms high specificity for L-histidinol, with no detectable activity toward analogues. The enzyme is essential for histidine production, and its deletion leads to complete auxotrophy. Its role in the final steps positions it as a potential bottleneck in the pathway, making it a candidate for overexpression or stabilization in engineered strains.
Other enzymes also exhibit unique characteristics. Phosphoribosyl-ATP pyrophosphatase (HisE) and phosphoribosyl-AMP cyclohydrolase (HisI) are encoded by separate genes in C. glutamicum, unlike in E. coli where they are fused. HisECg forms a dimer, consistent with M. tuberculosis HisEMt. The bifunctional His(IE) enzyme is absent in Actinobacteria, indicating horizontal gene transfer events during evolution.
5ProFAR isomerase (HisA) catalyzes an internal redox reaction converting 5ProFAR to PRFAR. HisACg acts as a monomer, adopting an (α/β)₈ barrel fold. Deletion of hisA causes strict histidine auxotrophy, confirming its essentiality. No evidence supports dual functionality in tryptophan biosynthesis, implying the presence of a separate phosphoribosylanthranilate isomerase encoded by trp(CF).
Imidazoleglycerol-phosphate dehydratase (HisB) converts IGP to imidazole-acetol phosphate (IAP) via a non-enzymatic ketonization step. HisBCg functions as a monomer and is structurally distinct from the bifunctional enzyme in E. coli. Its independence allows for decoupled regulation of early and late pathway steps.
In summary, the enzymatic network of histidine biosynthesis in C. glutamicum is marked by structural innovation, functional flexibility, and evolutionary divergence. The dispensability of hisH, the uniqueness of HisN, and the modularity of HisD offer compelling opportunities for strain engineering. Targeted modifications—such as feedback-resistant HisG mutants, overexpression of HisD, or optimization of transporter expression—can dramatically enhance histidine titers. Future work should focus on high-resolution structural characterization of HisFH and HisN, combined with in vivo dynamics studies, to fully exploit these insights for industrial biotechnology.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
The pursuit of effective treatments for neurodegenerative disorders has led to growing interest in epigenetic modulation, particularly through histone deacetylase (HDAC) inhibitors. These compounds aim to reverse aberrant gene silencing by increasing histone acetylation, thereby promoting transcriptional activation. In spinocerebellar ataxia type 1 (SCA1), where mutant ataxin-1 induces excessive repression of critical neuronal genes, HDAC inhibition was initially seen as a promising therapeutic strategy. However, our findings reveal a profound paradox: while HDAC3 is implicated in driving pathogenic transcriptional repression in SCA1, its complete removal—whether globally or specifically in Purkinje cells—leads to severe neurotoxicity and early-onset ataxia.
This contradiction underscores a fundamental challenge in epigenetic therapy: the same molecular machinery that contributes to disease can also be essential for neuronal survival. HDAC3 is not merely a passive executor of repression; it plays an active role in maintaining transcriptional homeostasis, regulating metabolic pathways, and supporting mitochondrial function in neurons.Vitamin D3-d3 manufacturer Our data show that conditional deletion of HDAC3 in PCs results in progressive loss of dendritic structure, thinning of the molecular layer, and eventual neuronal death—all occurring without detectable apoptosis. This suggests that HDAC3 supports vital cellular processes beyond chromatin remodeling, possibly including energy metabolism and stress response regulation.
Furthermore, the regional vulnerability observed in anterior versus posterior lobules raises questions about cell-type-specific dependencies on HDAC3. While SCA1 primarily affects lobules IX and X, HDAC3 knockout predominantly impacts anterior regions.Chrysene-d12 Epigenetic Reader Domain This discrepancy may stem from differential expression of co-regulators such as NCoR/SMRT, or variations in metabolic demand across cerebellar zones.PMID:34597384 It also implies that therapeutic targeting must consider anatomical and functional heterogeneity within the nervous system.
These results caution against broad or non-selective HDAC inhibition, especially in neurodegenerative contexts. The use of pan-HDAC inhibitors or even HDAC3-specific agents could inadvertently disrupt essential functions in vulnerable neurons, potentially worsening outcomes. Indeed, our study shows that even modest reductions in HDAC3 levels—such as those achieved via haploinsufficiency—are insufficient to rescue SCA1 phenotypes, while complete ablation causes catastrophic failure in PC integrity.
This highlights the need for more nuanced therapeutic approaches. Instead of systemic HDAC inhibition, future strategies should focus on identifying specific downstream targets of HDAC3 that are dysregulated in SCA1 but not essential for neuronal survival. Techniques such as chromatin immunoprecipitation sequencing (ChIP-seq), RNA-Seq, and single-cell profiling could help delineate these gene networks. Additionally, temporal control—such as pulse-dosing regimens or transient inhibition during early disease stages—may allow intervention before irreversible damage occurs, while minimizing long-term risks.
Moreover, the overlap between HDAC3 inhibition side effects and core symptoms of SCA1—such as ataxia, cognitive decline, and motor dysfunction—complicates clinical translation. In non-neuronal cancers, similar neurological side effects might be misattributed to metastases or paraneoplastic syndromes, leading to diagnostic confusion. Therefore, any clinical trial involving HDAC inhibitors must include rigorous monitoring for neurocognitive and motor changes.
In conclusion, while HDAC3 remains a compelling target in SCA1 due to its role in pathogenic transcriptional repression, our findings serve as a stark reminder that epigenetic modifiers are not inherently safe. Their therapeutic window is narrow, and their impact on neuronal health is context-dependent. Effective treatment will require not just inhibition, but precision—targeting only disease-relevant pathways while preserving the essential functions of HDAC3 in neuronal maintenance. Only then can we harness the power of epigenetics without triggering unintended neurodegeneration.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
In Caenorhabditis elegans, the formation of a functional vulval–uterine connection is essential for successful egg-laying. This connection relies on the precise specification of ventral uterine (VU) granddaughters into p cell fates, which subsequently give rise to the uterine seam cell (utse) and uv1 cells. Our study reveals that histone deacetylase hda-1 plays a pivotal role in this process by regulating signaling from the anchor cell (AC), the central organizer of uterine development. In hda-1 mutants, the utse fails to form, resulting in a defective or absent membrane at the apex of the vulva—a hallmark of disrupted morphogenesis.
To investigate this defect, we examined expression of p lineage-specific markers egl-13::gfp and lin-11::gfp in hda-1(RNAi) and hda-1(e1795) animals. In wild-type L3 larvae, six VU granddaughters adopt p fates, each giving rise to two daughters. By early L4 stage, these cells fuse with each other and the AC to form the utse. Both egl-13 and lin-11 are expressed in p cells and their progeny, and their activity is critical for proper division and fusion events. However, in hda-1 mutants, we observed a significant increase in the number of GFP-positive p-like cells—up to 10 in some animals—suggesting a failure to restrict p fate commitment. Furthermore, despite the increased number of p cells, their differentiation was impaired: the overall fluorescence intensity of lin-11::gfp was drastically reduced, and many cells lacked detectable expression altogether.
This paradoxical phenotype—more p-like cells but no functional utse—indicates that hda-1 is required not for p cell induction per se, but for their subsequent maturation and integration into the uterine structure. We also analyzed uv1 cell fate using ida-1::gfp, a marker specific to uv1 cells, which are derived from p progeny during L3 lethargus. In wild-type animals, four uv1 cells are clearly visible. In contrast, 96% of hda-1 mutants showed no ida-1::gfp expression, confirming a profound defect in uv1 specification. These findings demonstrate that hda-1 is essential for both p cell differentiation and the generation of downstream cell types necessary for a functional uterine–vulval junction.
The underlying mechanism involves hda-1’s function within the anchor cell. The AC produces the DSL ligand LAG-2, which activates LIN-12/Notch signaling in VU granddaughters to induce p fate. We found that hda-1 is expressed in the AC during mid-L3 stage, coinciding with the time of p cell induction. Knockdown of hda-1 led to a significant increase in lag-2::gfp fluorescence in the AC—by an average of 37%—indicating that hda-1 normally represses lag-2 expression.4-Chloro-6-fluoroquinazoline Biochemical Assay Reagents This overexpression likely causes ectopic activation of LIN-12/Notch signaling, leading to excessive p cell formation.Epacadostat Formula However, because these cells fail to differentiate properly, the net result is a loss of functional utse and uv1.PMID:35094218
To understand how hda-1 regulates lag-2, we investigated potential downstream effectors. We focused on two transcription factors known to act in the AC: nhr-67 and egl-43. Both are required for proper lag-2 expression and uterine cell fate specification. In hda-1(RNAi) animals, fluorescence of nhr-67::wcherry and egl-43::gfp in the AC was significantly reduced. Moreover, double RNAi experiments revealed that knockdown of either nhr-67 or egl-43 suppressed the elevated lag-2::gfp signal caused by hda-1 depletion. This genetic interaction demonstrates that nhr-67 and egl-43 act downstream of hda-1 to promote lag-2 expression, thereby mediating AC signaling.
These results support a model in which hda-1 functions as a transcriptional regulator in the AC to maintain appropriate levels of lag-2 through positive control of nhr-67 and egl-43. While hda-1 may also repress lag-2 in other contexts, its role in promoting lag-2 in the AC highlights a dual regulatory capacity. This balance ensures that LIN-12/Notch signaling is activated only when and where needed, preventing ectopic p cell formation while enabling correct uterine patterning.
In summary, our work establishes hda-1 as a key regulator of uterine cell fate specification. It acts in the anchor cell to fine-tune the expression of the LIN-12/Notch ligand lag-2 via nhr-67 and egl-43, thereby controlling the number and identity of p cells. This precise regulation is essential for the formation of the uterine seam cell and the integrity of the vulval–uterine connection. Given the conservation of HDAC1 and Notch pathway components across species, these findings provide insight into epigenetic mechanisms governing reproductive organ development and may inform understanding of related disorders in higher organisms.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
**Background**
Protein kinase C (PKC) is a family of serine/threonine kinases that play pivotal roles in various cellular processes, including signal transduction, gene expression, and cell proliferation. Dysregulation of PKC isoforms is often associated with a wide range of pathologies, including inflammation, cardiovascular diseases, and various forms of cancer. Similarly, glycogen synthase kinase-3 (GSK-3) is a key regulator of glucose metabolism and cellular signaling, and its overactivity is linked to several metabolic and neurodegenerative disorders. Given the critical roles of these kinases in disease progression, identifying potent and selective inhibitors is essential for developing therapeutic interventions. In this context, we will introduce a cell-permeable and reversible inhibitor – Bisindolylmaleimide I.
**Definition**
Bisindolylmaleimide I (GF109203X) hydrochloride is a cell-permeable and reversible PKC inhibitor with IC50 values of 20 nM for PKCα, 17 nM for PKCβI, 16 nM for PKCβII, and 20 nM for PKCγ. Additionally, it serves as an inhibitor of GSK-3.
**In Vitro and In Vivo Studies**
The Bisindolylmaleimide I description highlights its versatility as a kinase inhibitor across multiple biological systems. In terms of Bisindolylmaleimide I in vitro activity, the compound at 5 μM inhibits α-thrombin-induced P47 phosphorylation and reduces GSK-3 activity to 25.1±4.3% in adipocyte lysates. Furthermore, concentrations ranging from 0-1 μM inhibit DNA synthesis in quiescent Swiss 3T3 cells. In the context of Bisindolylmaleimide I Cancer research, treatment with 10 μM for 24 hours inhibits the release of exosomes and microvesicles (EMV) from PC3 cells and enhances the cytotoxicity of 5-fluorouracil.
Regarding Bisindolylmaleimide I In Vivo applications, the compound has demonstrated significant efficacy in various animal models. At a dose of 0.02 mg/kg (i.p.), it reduced the levels of NLRP3, P-PKCα, and PKCα in mechanical ventilation groups. In Quinpirole-treated shrews, administration of 0-20 mg/kg (i.p.) reduced the mean frequency of induced vomiting and blocked Quinpirole-mediated ERK1/2 phosphorylation in the brainstem. For researchers seeking detailed Bisindolylmaleimide I technical information, these results underscore the compound’s potency in modulating kinase-driven inflammatory and neurological responses. In conclusion, Bisindolylmaleimide I is a potent inhibitor of PKC and GSK-3 with broad applications in cellular and systemic research.
Keywords
Bisindolylmaleimide I, 176504-36-2, GF109203X, Go 6850, Go6850, Go-6850, PKC, GSK-3, Protein kinase C, Glycogen synthase kinase-3, Glycogen synthase kinase 3, Exosome, 3T3, adipocyte, 5-fluorouracil, P47, shrews, Inhibitor, inhibitor, inhibit
References
[1] Toullec D, et al. The bisindolylmaleimide GF 109203X is a potent and selective inhibitor of protein kinase C. J Biol Chem. 1991 Aug 25;266(24):15771-81.
[2] Vetri F, et al. Impairment of neurovascular coupling in Type 1 Diabetes Mellitus in rats is prevented by pancreatic islet transplantation and reversed by a semi-selective PKC inhibitor. Brain Res. 2017 Jan 15;1655:48-54.
[3] Hers I, et al. The protein kinase C inhibitors bisindolylmaleimide I (GF 109203x) and IX (Ro 31-8220) are potent inhibitors of glycogen synthase kinase-3 activity. FEBS Lett. 1999 Nov 5;460(3):433-6.
[4] Kosgodage US, et al. Chloramidine/Bisindolylmaleimide-I-Mediated Inhibition of Exosome and Microvesicle Release and Enhanced Efficacy of Cancer Chemotherapy. Int J Mol Sci. 2017 May 9;18(5):1007.
[5] Liu M, et al. Aerobic exercise alleviates ventilator-induced lung injury by inhibiting NLRP3 inflammasome activation. BMC Anesthesiol. 2022 Dec 1;22(1):369.
[6] Belkacemi L, et al. Signal transduction pathways involved in dopamine D2 receptor-evoked emesis in the least shrew (Cryptotis parva). Auton Neurosci. 2021 Jul;233:102807.
The A1chieve study, a global, non-interventional, 24-week observational trial, evaluated the real-world use of insulin analogues in patients with type 2 diabetes mellitus (T2DM). This report presents data from the South India cohort focusing on insulin detemir therapy, one of the most commonly prescribed basal insulin analogues. A total of 1,001 patients were included in this analysis—865 (86.4%) insulin-naïve and 136 (13.6%) insulin-experienced—enrolled across multiple centers in southern India.
At baseline, both groups exhibited suboptimal glycaemic control. The mean HbA1c was 9.6% in insulin-naïve patients and 9.2% in insulin users, reflecting persistent hyperglycemia despite prior oral glucose-lowering drug (OGLD) therapy. Patients had been managed with OGLDs for an average of 6–11 years, indicating long-standing disease burden and inadequate glucose control.CDH16 Protein Biological Activity
After 24 weeks of treatment with insulin detemir ± OGLDs, significant improvements were observed. In insulin-naïve individuals, HbA1c decreased from 9.6% to 8.1%, a reduction of -1.6%. Insulin users achieved a similar improvement, with HbA1c declining from 9.2% to 7.8%, a change of -1.3%. Fasting plasma glucose (FPG) fell from 10.8 mmol/L to 7.8 mmol/L, and postprandial glucose (PPPG) dropped from 16.2 mmol/L to 10.5 mmol/L, demonstrating effective day-long glucose management.
Hypoglycaemia remained a key safety concern, yet the incidence was remarkably low. In insulin-naïve patients, hypoglycaemia rates declined from 1.0 to 0.2 events per patient-year, while insulin users saw a reduction from 2.3 to 0.7 events per patient-year. Notably, no major hypoglycaemic episodes or serious adverse drug reactions (SADRs) were reported during the study period, underscoring the excellent safety profile of insulin detemir in this population.
Body weight showed a modest but consistent decline, decreasing from 70.8 kg to 69.8 kg in insulin-naïve patients and from 70.7 kg to 69.4 kg in insulin users. This contrasts with the typical weight gain associated with conventional insulin therapy, highlighting insulin detemir’s favourable metabolic effect.Celecoxib custom synthesis Quality of life, measured via the visual analogue scale (VAS), improved significantly—from 62.2 to 74.4 in insulin-naïve individuals and from 57.PMID:35114376 3 to 70.3 in insulin users—indicating enhanced well-being and treatment satisfaction.
Insulin dosing was stable over time, with daily doses increasing slightly from 14.9 U to 16.5 U in insulin-naïve patients and from 18.0 U to 19.3 U in insulin users. These adjustments reflect appropriate titration without overtreatment. Lipid profiles improved, with LDL-C levels decreasing and a higher proportion of patients achieving targets below 2.5 mmol/L. Systolic blood pressure also declined, from 139.9 mmHg to 128.8 mmHg, contributing to reduced cardiovascular risk.
In conclusion, insulin detemir demonstrated strong efficacy in improving glycaemic control in South Indian patients with T2DM, including those newly initiating insulin therapy. Its low risk of hypoglycaemia, neutral or beneficial impact on body weight, and positive effect on quality of life make it a preferred choice for basal insulin replacement. These findings support the integration of insulin detemir into routine clinical practice, particularly in populations where safety and tolerability are paramount.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
**Background**
Metabolic disorders, such as obesity and muscle atrophy, as well as various malignancies, remain significant challenges in global healthcare. The regulation of energy homeostasis and cellular proliferation often involves the activation of key signaling pathways, including the PI3K/Akt and AMPK pathways, as well as the modulation of Sirt1 and mitochondrial oxidative phosphorylation (OXPHOS). Targeting these pathways provides a strategic approach to treating muscle wasting, obesity, and tumor growth. In this context, we will introduce a potent prenyl flavonoid derived from the hop spike Humulus lupulus – 8-Prenylnaringenin.
**Definition**
8-Prenylnaringenin is an orally active prenyl flavonoid that acts as a SIRT1 activator and exhibits significant 8-Prenylnaringenin Biological Activity across various physiological systems. It is characterized by the 8-Prenylnaringenin Formula C20H20O5 and a molecular weight of 340.37.
**In Vitro and In Vivo Studies**
The 8-Prenylnaringenin Description highlights its multi-target efficacy. In 8-Prenylnaringenin In Vitro studies, the compound demonstrated strong antiproliferative effects against human colon cancer HCT-116 cells with an IC50 value of 23.83 μg/mL. In human glioblastoma U-118 MG cells, it showed cytotoxicity with an IC50 of approximately 138 μM, which was higher than that observed in normal BJ fibroblasts (IC50 = 172 μM). Furthermore, 8-Prenylnaringenin (0.001-20 μM; 48 h) reduced ROS production and SOD activity in MCF-7 breast cancer cells, while upregulating Sirt1 and OXPHOS complexes II, III, and V. It also inhibited BME cell invasion (IC50: 3-10 μM) and dose-dependently inhibited angiogenesis induced by bFGF and VEGF.
In 8-Prenylnaringenin In Vivo experiments, the compound showed significant therapeutic potential. In C57/BL6 mice, oral administration (0.00005-0.0005% wt/wt in diet) promoted recovery from immobilization-induced disuse muscle atrophy by activating the Akt phosphorylation pathway. In C57BL/6J male mice fed a high-fat diet, 8-Prenylnaringenin (0.0005%-0.005% wt/wt; 8 weeks) prevented obesity and fat accumulation in white adipose tissue by promoting adiponectin secretion and activating the AMPK pathway, which subsequently regulated SREBP-1 and PGC-1α expression. Additionally, in ovariectomized Sprague-Dawley rats, it suppressed serum LH/FSH levels and stimulated uterine weight. Regarding 8-Prenylnaringenin Cancer research, its ability to inhibit tumor cell proliferation and angiogenesis makes it a valuable tool for oncology studies. In conclusion, 8-Prenylnaringenin is a versatile prenyl flavonoid with potent activities in metabolic regulation and anticancer research.
Keywords
8-Prenylnaringenin, 53846-50-7, PI3K, Akt, AMPK, Sirtuin, Reactive Oxygen Species (ROS), SOD, Phosphoinositide 3-kinase, PKB, Protein kinase B, AMP-activated protein kinase, Superoxide Dismutase, Inhibitor, inhibitor, inhibit
References
[1] Koosha S, et al. Antiproliferative and apoptotic activities of 8-prenylnaringenin against human colon cancer cells. Life Sci. 2019 Jul 3:116633.
[2] Mukai R, et al. 8-Prenylnaringenin promotes recovery from immobilization-induced disuse muscle atrophy through activation of the Akt phosphorylation pathway in mice. Am J Physiol Regul Integr Comp Physiol. 2016 Dec 1;311(6):R1022-R1031.
[3] Stompor M, et al. In Vitro Effect of 8-Prenylnaringenin and Naringenin on Fibroblasts and Glioblastoma Cells-Cellular Accumulation and Cytotoxicity. Molecules. 2017 Jun 30;22(7).
[4] Blanquer-Rosselló MM, et al. Effect of xanthohumol and 8-prenylnaringenin on MCF-7 breast cancer cells oxidative stress and mitochondrial complexes expression. J Cell Biochem. 2013 Dec;114(12):2785-94.
[5] Pepper MS, et al. 8-prenylnaringenin, a novel phytoestrogen, inhibits angiogenesis in vitro and in vivo. J Cell Physiol. 2004 Apr;199(1):98-107.
[6] Okada F, et al. 8-Prenylnaringenin suppresses obesity in high-fat diet-fed C57BL/6J mice via adiponectin secretion. J Clin Biochem Nutr. 2025 Jul;77(1):64-73.
[7] Christoffel J, et al. Effects of 8-prenylnaringenin on the hypothalamo-pituitary-uterine axis in rats after 3-month treatment. J Endocrinol. 2006 Mar;188(3):397-405.
[8] Hoffmann DB, et al. Effects of 8-Prenylnaringenin and Whole-Body Vibration Therapy on a Rat Model of Osteopenia. J Nutr Metab. 2016;2016:6893137.
**Background**
Human Immunodeficiency Virus (HIV) is a retrovirus that attacks the immune system, specifically CD4+ T cells, leading to Acquired Immunodeficiency Syndrome (AIDS). The replication cycle of HIV involves the reverse transcription of viral RNA into DNA, a process that is critical for the integration of the viral genome into the host cell’s DNA. Consequently, targeting the reverse transcription process has been a primary strategy in the development of antiretroviral therapies. Effective inhibition of viral replication is essential to reduce viral load and prevent the progression of the disease. In this context, we will introduce a potent inhibitor of HIV replication – 2′,3′-Dideoxyadenosine.
**Definition**
2′,3′-Dideoxyadenosine is an antiretroviral compound that acts as an inhibitor of HIV replication, demonstrating significant antiviral efficacy against multiple strains of the virus.
**In Vitro Studies**
According to the 2′,3′-Dideoxyadenosine technical information, this compound exhibits broad-spectrum activity against various retroviruses. In 2′,3′-Dideoxyadenosine in vitro assays, it inhibits HIV-1 and simian immunodeficiency virus (SIV) in MT-4 cells with $\text{EC}_{50}$ values of 5.27 $\mu\text{M}$ and 5.3 $\mu\text{M}$, respectively. In human T-lymphocyte CEM cells, it inhibits HIV-1 and HIV-2 with $\text{EC}_{50}$ values of 4 $\mu\text{M}$ and 8 $\mu\text{M}$, respectively. Furthermore, in Molt 4/C8 cells, the $\text{EC}_{50}$ values for HIV-1 and HIV-2 inhibition are 4 $\mu\text{M}$ and 5.5 $\mu\text{M}$, while in C8166 cells, the values are 17 $\mu\text{M}$ and 22 $\mu\text{M}$. Beyond HIV, 2′,3′-Dideoxyadenosine biological activity extends to the inhibition of murine sarcoma virus (MSV) in C3H/3T3 cells with an $\text{EC}_{50}$ of 24 $\mu\text{M}$. Regarding cytotoxicity, the $\text{CC}_{50}$ in human CEM cells is reported to be $> 250 \mu\text{M}$, and in MT-4 cells, it is approximately 890 $\mu\text{M}$, indicating a favorable therapeutic window. In conclusion, 2′,3′-Dideoxyadenosine is a potent antiviral agent effective against HIV-1, HIV-2, and SIV.
Keywords
2′,3′-Dideoxyadenosine, 4097-22-7, HIV, Human immunodeficiency virus, Inhibitor, inhibitor, inhibit
References
Apoptosis, or programmed cell death, is a tightly regulated process essential for maintaining cellular homeostasis and preventing uncontrolled proliferation. In cancer, evasion of apoptosis is a hallmark feature that enables tumor cells to survive despite genetic damage and stress signals. Melittin (MEL), a major component of bee venom, has emerged as a potent inducer of apoptosis in various cancer types, including cervical carcinoma. This study investigates the molecular mechanisms by which melittin triggers apoptosis and induces cell cycle arrest in human cervical cancer CaSki cells.
Treatment with melittin led to a significant reduction in cell viability in a dose- and time-dependent manner, as confirmed by MTT and WST-1 assays. At concentrations ranging from 0.5 to 2 μg/mL, melittin effectively inhibited proliferation without causing substantial toxicity at lower doses, suggesting a therapeutic window. Flow cytometry analysis revealed that melittin induced G2/M phase cell cycle arrest, accompanied by a marked increase in the sub-G1 population, indicative of DNA fragmentation and apoptotic cell death.
Mechanistically, melittin activated key components of the intrinsic apoptotic pathway. Western blot analysis showed a progressive increase in cleaved caspase-9 and caspase-3, along with a decrease in pro-caspase forms. Concurrently, the levels of anti-apoptotic proteins Bcl-2 and Bcl-xL were significantly downregulated, while the pro-apoptotic protein Bax was upregulated. This shift in the Bcl-2/Bax ratio promoted mitochondrial outer membrane permeabilization (MOMP), leading to cytochrome c release into the cytosol. The subsequent formation of the apoptosome complex triggered caspase-9 activation, initiating the execution phase of apoptosis.
Further evidence was provided by caspase activity assays, which demonstrated a strong dose-dependent activation of caspase-3 and caspase-9 following melittin treatment. Pretreatment with pan-caspase inhibitor Z-VAD-FMK significantly attenuated apoptosis, confirming the critical role of caspases in mediating melittin-induced cell death.Pimicotinib site Additionally, melittin induced PARP cleavage, a hallmark of apoptotic execution, further supporting the activation of the caspase cascade.Alogliptin Protocol
In parallel, melittin suppressed the expression of cyclin-dependent kinases (CDKs) and cyclins involved in G2/M transition.PMID:34904508 Specifically, the levels of CDK1, CDK2, cyclin B1, and cyclin A were markedly reduced after melittin exposure. This downregulation disrupted the assembly of functional CDK-cyclin complexes necessary for cell cycle progression, thereby contributing to the observed G2/M arrest. Phosphorylation of retinoblastoma protein (Rb) was also diminished, indicating inhibition of the G1/S transition, although the primary arrest occurred at G2/M.
Immunofluorescence staining revealed nuclear condensation and fragmentation in melittin-treated cells, consistent with apoptotic morphology. Moreover, transmission electron microscopy showed characteristic ultrastructural changes, including chromatin margination and membrane blebbing, further validating apoptosis induction.
These findings demonstrate that melittin exerts dual anticancer effects in CaSki cells: it activates caspase-dependent apoptosis via mitochondrial dysfunction and inhibits cell cycle progression by suppressing CDK/cyclin activity. The selective targeting of these pathways suggests that melittin may overcome resistance mechanisms commonly seen in chemotherapy-resistant cancers. Given its ability to induce apoptosis without affecting normal cells at therapeutic doses, melittin holds promise as a natural agent for cervical cancer therapy. Future studies should focus on optimizing delivery systems and evaluating efficacy in vivo to advance its potential clinical application.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
The development of functional enzymes capable of operating effectively in human physiological environments is a cornerstone of modern biotechnology, particularly in the design of implantable biosensors and biofuel cells. In this context, high-redox potential laccases (HRPLs) from basidiomycetes offer unique advantages due to their ability to catalyze oxygen reduction at high potentials. However, their natural susceptibility to inhibition by hydroxide ions and halides—abundant in blood—has limited their practical use. To overcome these barriers, we engineered a blood-tolerant laccase variant, ChU-B, through iterative directed evolution in Saccharomyces cerevisiae, and subsequently optimized its overexpression in Pichia pastoris for scalable production.
The ChU-B mutant was constructed by fusing the mature laccase domain of PM1 strain CECT 2971 to either native or evolved α-factor prepro-leader sequences. These constructs were cloned under two distinct promoters: PAOX1 (methanol-inducible) and PGAP (constitutive). Initial screening in shake-flask cultures identified the PAOX1-driven construct with the evolved prepro-leader as the most productive. This candidate was then subjected to small-scale fed-batch fermentation in a 500-mL bioreactor, achieving peak laccase activity of 990 ABTS-U/L after 151 hours of induction. Encouraged by these results, the process was scaled up to a 42-L bioreactor system using a 20-L fermentation volume. The final yield reached 43 mg/L of purified recombinant enzyme, marking a 5.4-fold increase over S. cerevisiae-based production (~8 mg/L).
Purification of the ChU-B laccase involved a three-step chromatographic protocol: ammonium sulfate precipitation, anion-exchange (Mono Q), and hydrophobic interaction chromatography (PHE sepharose). The resulting protein was homogeneous, as confirmed by SDS-PAGE and MALDI-TOF mass spectrometry. The molecular weight of the P. pastoris-produced enzyme was determined to be 62,541 Da, consistent with the presence of additional glycosylation compared to the S. cerevisiae version (60,310 Da). Glycosylation levels were estimated at 16% in P. pastoris versus 12% in S. cerevisiae, reflecting differences in post-translational processing between hosts.
Despite higher glycosylation, the enzyme retained full functionality. N-terminal sequencing revealed identical extra extensions (ETEAEF) in both expression systems, indicating incomplete cleavage of the α-factor pro-leader by STE13 protease—a phenomenon observed in both yeasts. This extension did not impair activity but may contribute to secretion efficiency. The pH-activity profile remained unchanged across hosts, with optimal activity at pH 4.0 (ABTS) and pH 5.0 (DMP), and significant residual activity at pH 7.4. Most notably, the ChU-B mutant exhibited exceptional resistance to halide inhibition: I50 values for Cl⁻ exceeded 1000 mM at acidic pH, and F⁻ inhibition was also substantially reduced.Bis(4-tert-butylphenyl)amine Cancer
Kinetic analysis demonstrated that Km values for ABTS and DMP were similar between the two hosts (~0.024 mM and ~0.26 mM, respectively), indicating no loss in substrate affinity.STAT3 Antibody manufacturer However, kcat values were consistently higher in the S.PMID:35086724 cerevisiae-expressed form, suggesting subtle differences in catalytic turnover possibly linked to glycosylation patterns or folding dynamics. Still, the overall catalytic efficiency remained sufficient for biomedical applications.
Functional validation in human plasma and whole blood confirmed the enzyme’s real-world utility. Oxygen consumption rates were measured using a Clark electrode, yielding values of 31 ± 7 min⁻¹ in blood and 27 ± 1 min⁻¹ in plasma—indicating robust activity in complex biological matrices without interference from serum proteins or cellular components. This performance underscores the enzyme’s suitability for integration into miniature biofuel cells and continuous monitoring devices.
In conclusion, the combination of directed evolution in S. cerevisiae followed by high-level expression in P. pastoris provides a scalable, efficient, and reliable platform for producing advanced biocatalysts. The ChU-B laccase exemplifies how rational engineering can transform a naturally sensitive enzyme into a stable, blood-compatible biocatalyst. Its successful production and characterization pave the way for future applications in implantable diagnostics, wearable sensors, and energy-harvesting devices operating within the human body.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
Intrauterine growth restriction (IUGR) is increasingly recognized as a condition with profound implications for fetal metabolic programming, predisposing individuals to insulin resistance, obesity, and cardiovascular disease in adulthood. Central to this process are adipocytokines—bioactive molecules secreted by adipose tissue that regulate energy homeostasis, inflammation, and insulin sensitivity. Among these, adiponectin and leptin play opposing roles: adiponectin exerts anti-inflammatory and insulin-sensitizing effects, while leptin primarily regulates appetite and energy balance but also contributes to immune activation and endothelial dysfunction when dysregulated. This study investigates the maternal-fetal serum levels of adiponectin and leptin in IUGR, small-for-gestational-age (SGA), and appropriate-for-gestational-age (AGA) pregnancies, aiming to clarify their role in metabolic and vascular adaptation during fetal development.
A retrospective cohort analysis was conducted on 140 pregnant women from the University of Padua between January 2011 and March 2013. Participants were stratified into three groups: 37 IUGR (EFW < 10th percentile with abnormal umbilical artery Doppler), 33 SGA (EFW < 10th percentile without Doppler abnormalities), and 70 AGA (EFW ≥ 10th percentile). Blood samples were collected at delivery from both mothers and umbilical cords. Serum concentrations of adiponectin and leptin were measured using radioimmunoassay kits with high analytical precision. Adiponectin levels were determined via Millipore RIA kit (HADP-61HK), with a sensitivity of 1 μg/L and measuring range of 1–240 μg/L. Leptin was assessed using Mediagnost’s streptavidin-coated tube assay, with sensitivity of 0.1 μg/L and a dynamic range of 0.1–64 μg/L. Results revealed a striking imbalance in adipocytokine profiles among IUGR fetuses. Fetal adiponectin levels were significantly lower in IUGR compared to both SGA (p < 0.05) and AGA (p < 0.05) groups, with median values of 134 μg/L versus 197 μg/L and 196 μg/L, respectively. Conversely, fetal leptin levels were markedly elevated in IUGR fetuses (median 7.1 μg/L) compared to SGA (4.3 μg/L) and AGA (4.9 μg/L) (p < 0.05). The adiponectin-to-leptin ratio (A/L ratio), considered a key indicator of metabolic risk, was significantly reduced in IUGR fetuses (median 17.4) compared to SGA (43.5) and AGA (41.3) (p < 0.05). Maternal findings mirrored those in the fetus. Maternal adiponectin was significantly lower in IUGR women (median 45 μg/L) than in SGA (58 μg/L) and AGA (57 μg/L) (p < 0.05). Maternal leptin was highest in IUGR (8.2 μg/L), followed by SGA (8.5 μg/L), and lowest in AGA (5.5 μg/L) (p < 0.05). These results suggest a systemic shift toward a pro-inflammatory and metabolically unfavorable state in IUGR pregnancies. Correlation analyses demonstrated that fetal adiponectin positively correlated with gestational age at delivery (p < 0.05) and birth weight (p < 0.05), indicating its physiological importance in normal fetal development.Triisopropyl Autophagy In contrast, fetal leptin showed a positive correlation with aIMT (p < 0.BCL6 Antibody In Vitro 05), suggesting a direct link between increased leptin and vascular remodeling.PMID:35155866 Furthermore, the A/L ratio exhibited a significant negative correlation with aIMT in IUGR fetuses (p < 0.05), reinforcing the hypothesis that an imbalance between adiponectin and leptin may drive early atherosclerotic changes. The pathophysiological mechanisms underlying these findings involve multiple pathways. Reduced adiponectin impairs insulin signaling and promotes inflammation by failing to suppress macrophage activation and cytokine release. Elevated leptin contributes to oxidative stress, endothelial dysfunction, and increased vascular tone. Together, they create a permissive environment for vascular damage, even in the absence of overt hyperglycemia or hypertension. These results highlight the critical role of adipocytokine dysregulation in the developmental origins of health and disease. The observed imbalance in adiponectin and leptin in IUGR fetuses may represent an adaptive response to nutrient scarcity, but one that carries long-term risks. Early identification of this profile could enable targeted interventions, such as maternal nutritional optimization or postnatal monitoring of metabolic parameters, to mitigate future disease burden. In conclusion, IUGR is associated with a distinct adipocytokine signature characterized by low adiponectin, high leptin, and a reduced A/L ratio. This imbalance correlates with increased vascular thickness and systemic inflammation, suggesting a mechanistic link between fetal metabolic programming and adult-onset cardiovascular disease. Future research should explore whether modulating this axis during pregnancy can improve long-term outcomes for affected offspring.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com