The current article deals with the in-silico along with enzyme kinetics approach to search for a prominent AChE enzyme inhibitor among the known natural compounds. The computational tools were involved for this purpose and eventual vincamine, a monoterpenoid indole alkaloid, was selected based on several parameters, including free energy of binding (-10.77 kcal/mol) and ADME parameter. Computationally, it confirmed the interaction between vincamine and AChE at an indistinguishable locus from that of substrate AChI (-3.94 kcal/mol) but with much higher binding energy. Interestingly, amino acid residues Gly120, Gly121, Gly122, Glu202, Trp86, Tyr133, Ser203, Phe297, and His447 of AChE were found to be common in these interactions. Further, these findings were approved with wet lab tests where detailed kinetics was studied. It was found that vincamine inhibited AChE with the inhibition constant Ki (239 µM). The value of IC50 (239 µM) and KM (0.598 mM) was determined and further confirmed by Dixon, Lineweaver- Burk reciprocal, Hanes, and Eadie- Hofstee plots, respectively. The mode of interaction of the compound was found to be competitive for AChE. Thus, the present computational and enzyme kinetics studies conclude that vincamine can be a promising inhibitor of AChE for the effective management of AD.
Lanthipeptides are ribosomally synthesized and post-translationally modified peptides (RiPPs) characterized by the presence of thioether cross-links called lanthionine and methyllanthionine, formed by dehydration of Ser/Thr residues and Michael-type addition of Cys side chains onto the resulting dehydroamino acids. Class II lanthipeptide synthetases are bifunctional enzymes responsible for both steps, thus generating macrocyclic natural products. ProcM is part of a group of class II lanthipeptide synthetases that are known for their remarkable substrate tolerance, having large numbers of natural substrates with highly diverse peptide sequences.
Genetically encoded noncanonical amino acids can introduce new-to-nature activation modes into enzymes. While these amino acids can act as catalysts on their own due to their inherent chemical properties, interactions with adjacent residues in an enzyme, such as those present in natural catalytic dyads or triads, unlock a higher potential for designer enzymes. We incorporated a boron-containing amino acid into the protein scaffold RamR to create an active enzyme for the kinetic resolution of α-hydroxythioesters.
The 3-chymotrypsin-like protease (3CL-PR; also known as Main protease) of SARS-CoV-2 is a cysteine protease that is the target of the COVID-19 drug, Paxlovid. Here, we report for 3CL-PR, the pH-rate profiles of a substrate, an inhibitor, affinity agents, and solvent kinetic isotope effects (sKIEs) obtained under both steady-state and pre-steady-state conditions. "Bell-shaped" plots of log( / ) vs pH for the substrate (Abz)SAVLQ*SGFRK(Dnp)-NH and p vs pH for a peptide aldehyde inhibitor demonstrated that essential acidic and basic groups of p = 8.
Collaborative Innovation Center of Targeted Development of Medicinal Resources (iCTM) & Research Center of Aquatic Organism Conservation and Water Ecosystem Restoration, Anqing Normal University, Anqing, China.
UDP-glucuronosyltransferases (UGTs) are responsible for inactivation of a variety of drugs, endogenous hormones and environmental toxicants. Chemical inhibitors are a common factor decreasing UGT activities and furtherly inducing health problems. Although simultaneously encountering different inhibitors is readily to occur, no information is available for combined inhibition of UGT.
Macrophages are versatile myeloid leukocytes with flexible cellular states to perform diverse tissue functions beyond immunity. This plasticity is however often hijacked by diseases to promote pathology. Scanning kinetics of macrophage states by single-cell transcriptomics and flow cytometry, we observed atopic dermatitis drastically exhausted a resident subtype S1.
