The human cytochrome P450 CYP17A1 plays a critical role in the production of steroid hormones, converting pregnenolone to dehydroepiandrosterone and progesterone to androstenedione. Sequential reactions catalyzed by CYP17A1 are hydroxylation at C17 position, followed by C17 - C20 carbon‑carbon bond scission. The mechanism of the lyase reaction is still debated, with two proposed reaction pathways favoring either a peroxo- (Compond 0) or iron-oxo (Compound 1) driven catalysis. In this review we summarize the results obtained through collaboration between the Sligar laboratory at University of Illinois and the Kincaid laboratory at Marquette University over the last 15years. We used a combination of spectroscopic and functional studies of human CYP17A1 incorporated in lipid Nanodiscs, mimicking the native membrane environment, to dissect the elementary steps of P450 reaction cycle and characterize the iron‑oxygen intermediates in the presence of substrates for both reactions catalyzed by CYP17A1. In addition, we used the mutations E305G and T306A to probe the effect of perturbing the proton delivery required for the formation of Compound 1, but not for Compound 0, and the mutation N202S involved in substrate positioning at the active site. Resonance Raman spectra, in combination with cryo-radiolytic reduction of the oxy-complex of CYP17A1, provided a detailed picture of hydrogen bonding and protonation of peroxo- and hydroperoxo- intermediates and identified a new transient hemiketal complex on the peroxo-driven pathway of lyase reaction. These results consistently demonstrated the predominant role of the peroxo-driven catalysis for the lyase reaction in CYP17A1 incorporated in lipid Nanodiscs.

Spectroscopic characterization of Mn2+-induced catalysis in cyclic GMP-AMP synthase.

Synergistic activation of bimetallic sulfides via hierarchical architecture: a superior bifunctional electrocatalyst for efficient hydrogen evolution and iodine reduction.

Novel antioxidant peptides identified from wheat germ protein: Structure-activity relationships, stability, and cytoprotective ability.

Hypercholesterolemia is a major modifiable risk factor for cardiovascular disease, largely driven by excessive activity of 3-hydroxy-3-methylglutaryl-CoA reductase (Hmgcr), the rate-limiting enzyme in cholesterol biosynthesis. Although statins are effective inhibitors of this enzyme, their long-term use is often limited by their adverse effects. This has encouraged the search for safer, plant-derived alternatives. Withania coagulans, a medicinal plant rich in withanolides, has demonstrated lipid-lowering potential; however, its molecular interactions with Hmgcr remain insufficiently explored. This study aimed to identify and characterize bioactive compounds from Withania coagulans as potential natural inhibitors of Hmgcr in Mus musculus, using an integrated in silico strategy. A validated three-dimensional model of Mus musculus Hmgcr was generated using homology modeling. Twenty bioactive compounds from Withania coagulans, along with standard statins, were screened using molecular docking and ADMET profiling, following Lipinski's rule of five. High-ranking complexes were further explored using MM/PBSA and MM/GBSA binding-free energy calculations. Molecular dynamics simulations (100 ns) were performed for top-ranked selected ligand-protein complexes to assess their structural stability and interaction persistence under physiologically relevant conditions. Several Withania coagulans compounds demonstrated strong binding affinities toward the Hmgcr active site, in some cases comparable to or exceeding those of standard statins. The key interactions involved conserved catalytic residues, such as Tyr516, Met533, Ile535, Ile761, Pro812 and Gln813. Molecular dynamics analyses revealed stable complexes with low RMSD fluctuations and minimal active site flexibility, confirming sustained ligand binding. ADMET predictions suggested favorable oral absorption and acceptable drug-like properties for the leading compounds. This study highlights Withania coagulans as a promising source of natural Hmgcr inhibitors. The identified compounds exhibited stable binding, favorable pharmacokinetic profiles, and mechanistic similarity to established statins, supporting their potential for further experimental validation as cholesterol-lowering agents.

Interfacial electronic tuning and polarization effects enhance Na+ ion storage performance of covalent organic frameworks with maximized active site loading on graphene.

Antiviral constituents of the Korean endemic plant Irisodaesanensis inhibit hepatitis C virus through multiple targets.

Chiral metal nanozyme-enabled SOD2 activation and siRNA delivery cooperatively mitigating chronic heart failure.

Targeting cholinesterases with steroid hormone derivatives: Insights from In Vitro assays and molecular modeling.

Herein, we report the expression of split BURP domain peptide cyclases (BpCs), primarily CamB1 from Ceanothus americanus, in Escherichia coli using the pET22b vector without a fusion partner while retaining their disordered N-terminal region. To our knowledge, this represents the first full-length split BpC expressed and isolated without reliance on a stabilizing fusion tag (e.g., maltose binding protein, MBP). Both CamB1 and ArbB2, from Coffea arabica, were purified and refolded from inclusion bodies, and displayed robust catalytic turnover on a minimal peptide substrate. Copper titrations revealed that catalytic assays using glutathione as the reducing agent require copper far in excess of the stoichiometric number of active sites, with activity plateauing at ∼50-fold excess, likely reflecting competition with nonspecific copper binding or solution speciation. Using ascorbic acid in place of glutathione not only restores but also increases maximal activity, requiring only near-stochiometric copper. Metal impact studies demonstrated that noncognate metals inhibit activity. Zn(II) most severely inhibited BpC function at low micromolar concentrations in enzyme-initiated assays containing Cu(II), Zn(II), and glutathione, but this effect was markedly alleviated in reducing agent-initiated assays and instead resembled the modest inhibition by Ag(I), which fully suppressed activity only near 1mM. These results highlight how assay order influences metal competition at the active site. Given that BURP-domain proteins are implicated in plant stress responses, including tolerance to metal exposure, these findings suggest that Zn(II) and Ag(I) inhibition may represent a biochemical mechanism by which environmental metal stress modulates BpC activity.

Introduction: Transcranial Direct Current Stimulation (tDCS) is a technique used to regulate neural activity by applying a lowlevel electrical current to specific brain regions. It modulates neuronal excitability and activity without directly inducing action potentials. The effects of tDCS are dependent on the type of current used, with anodal stimulation generally increasing and cathodal stimulation decreasing the excitability of brain cells. Aim: To determine the efficacy of tDCS in improving the dualtask cognitive function. Materials and Methods: This randomised clinical trial was conducted in the Maharishi Markandeswar Institute of Physiotherapy and Rehabilitation, Mullana, Ambala, Haryana, India, a tertiary health care centre, from August 2022 to April 2023. This study was conducted with 32 participants, dividing them into four groups, each receiving a different level of tDCS intensity (0.5 mA for Group A, 1.0 mA for Group B, 1.5 mA for Group C, and 2.0 mA for Group D). The stimulation was applied to the F3 region (active site) and F4 region (control site) of the frontal cortex, following the 10-20 Electroencephalography (EEG) system. Each session lasted 20 minutes and took place three times a week over a period of three weeks. Throughout the study, participants performed dual-task cognitive exercises, and their cognitive function was assessed both before and after the intervention using the Montreal Cognitive Assessment (MoCA) and Trail Making Test (TMT). Finally, data analysis was performed using Statistical Package for Social Sciences (SPSS) 26.0 software. For datasets satisfying the assumptions of parametric testing, a paired t-test was utilised for within-group comparisons, while an One-way Analysis of Variance (ANOVA) test was used to evaluate group variations. Results: It was assessed whether the demographic data and outcome measures followed a normal distribution, using the Shapiro-Wilk test. The analysis showed no statistically significant between-group dfferences in cognitive performance among healthy participants groups exposed to varying intensities of t-DCS. Although slight fluctuations were observed in the mean MoCA and TMT-A and TMT-B scores across different groups, the p-values remained above the standard level of significance (p-value>0.05). This suggests that the different intensities of t-DCS did not produce a statistically significant effect on cognitive function. Conclusion: The present study found no significant differences in cognitive performance across the various tDCS intensity levels, suggesting that the tested parameters may not have a substantial impact on cognitive function in healthy individuals.

Dynamic active site reconstruction dictates the oxygen evolution reaction performance of cobalt-based electrocatalysts.

Biochar colloids facilitate magnesium migration and transformation in soil: Active site competition coupling with mineral magnesium release

Widening the ammonia selective catalytic reduction window over copper-based SSZ-39 zeolites: Synergy of copper(II) ions and copper oxide clusters.

Porous carbon sphere supported Sv-CuIn5S8: a triple-engineered platform for high-efficiency photocatalytic CO2 conversion.

Revolutionizing protein degradation: Harnessing nanoparticles for PROTAC delivery.

Antioxidase-mimetic artificial biotubes for anti-inflammatory healing and regeneration of vascular injury.

Matching molecular scale with active site spacing induces distinct mechanisms in single-atom catalysts for persulfate activation

Bridged planar [Ni(CN)4]2- coordination active site to promote photocatalytic hydrogen evolution of transition metal sulfides

Engineering electronic structure to modulate active site environment for enhanced photocatalytic nitrogen fixation