SARS-CoV-2 3CL protease (Main protease) and human cathepsin L are proteases that play unique roles in the infection of human cells by SARS-CoV-2, the causative agent of COVID-19. Both proteases recognize leucine and other hydrophobic amino acids at the P position of a peptidomimetic inhibitor. At the P position, cathepsin L accepts many amino acid side chains, with a partial preference for phenylalanine, while 3CL-PR protease has a stringent specificity for glutamine or glutamine analogues.
View Article and Find Full Text PDFGlutamate dehydrogenase (GDH) is a homohexameric enzyme that catalyzes the reversible oxidative deamination of l-glutamate. While GDH is found in all living organisms, only that from animals is highly allosterically regulated by a wide array of metabolites. Because only animal GDH has a 50-residue antenna domain, we hypothesized that it was critical for allostery.
View Article and Find Full Text PDFBasic side chains play crucial roles in protein-DNA interactions. In this study, using NMR spectroscopy, we investigated the dynamics of Arg and Lys side chains of the fruit fly Antennapedia homeodomain in the free state and in the complex with target DNA. We measured N relaxation for Arg and Lys side chains at two magnetic fields, from which generalized order parameters for the cationic groups were determined.
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