Dissecting Methionine Oxidation by Hydrogen Peroxide in Proteins: Thermodynamics, Kinetics, and Susceptibility Descriptors.

The oxidation of Met residues in proteins is a complex process, where protein-specific structural and dynamical features play a relevant role in determining the reaction kinetics. Aiming to a full-side perspective, we report here a comprehensive characterization of Met oxidation kinetics by hydrogen peroxide in a leptin protein case study. To do that, we estimated the reaction-free energy profile of the Met oxidation via a QM/MM approach, while the kinetics of the formation of the reactive species were calculated using classical molecular dynamics (MD) simulations.

Modulating Charge Transfer Kinetics along Poly Adenine: Chemical Modifications, Temperature, and Conformational Effects.

The charge transfer (CT) reactions in nucleic acids are crucial for genome damage and repair and nanoelectronics using DNA as a molecular conductor. Previous experimental and theoretical works underlined the significance of nucleic acid structural dynamics on CT kinetics, requiring models that incorporate the dynamics of the nucleic acid, solvents, and counterions. Here, we investigated hole transfer kinetics in poly adenine single and double strands at various temperatures and the rate enhancement due to adenine-to-7-deazaadenine mutation by means of a QM/MM approach.

Post-myocardial infarction ventricular septal defects: incidence and treatment trends during and after the COVID-19 pandemic.

Ventricular septal defect (VSD) is a serious complication of myocardial infarction (MI), with its global incidence significantly reduced in recent years due to advances in coronary reperfusion techniques. However, during the COVID-19 pandemic, there was an unexpected rise in the incidence of post-MI VSD, likely driven by delays in seeking treatment. This study retrospectively analyzed 10 cases of post-MI VSD treated at our hospitals from March 2018 to August 2023, comparing incidence rates across pre-pandemic, pandemic, and post-pandemic periods.

Theoretical Insights into MutY Glycosylase DNA Repair Mechanism.

Maintaining the integrity of the genome is fundamental to living organisms. To this end, nature developed several mechanisms to find and promptly repair DNA lesions. Among them, base excision repair (BER) enzymes evolved to efficiently carry out this task.

Binding of steroid substrates reveals the key to the productive transition of the cytochrome P450 OleP.

OleP is a bacterial cytochrome P450 involved in oleandomycin biosynthesis as it catalyzes regioselective epoxidation on macrolide intermediates. OleP has recently been reported to convert lithocholic acid (LCA) into murideoxycholic acid through a highly regioselective reaction and to unspecifically hydroxylate testosterone (TES). Since LCA and TES mainly differ by the substituent group at the C17, here we used X-ray crystallography, equilibrium binding assays, and molecular dynamics simulations to investigate the molecular basis of the diverse reactivity observed with the two steroids.