Evaluation of kinetic data: What the numbers tell us about PRMTs

Publication date: Available online 17 October 2018Source: Biochimica et Biophysica Acta (BBA) - Proteins and ProteomicsAuthor(s): Adam Frankel, Jennifer I. BrownAbstractProtein arginine N-methyltransferase (PRMT) kinetic parameters have been catalogued over the past fifteen years for eight of the nine mammalian enzyme family members. Like the majority of methyltransferases, these enzymes employ the highly ubiquitous cofactor S-adenosyl-l-methionine as a co-substrate to methylate arginine residues in peptidic substrates with an approximately 4-μM median KM. The median values for PRMT turnover number (kcat) and catalytic efficiency (kcat/KM) are 0.0051 s−1 and 708 M−1 s−1, respectively. When comparing PRMT metrics to entries found in the BRENDA database, we find that while PRMTs exhibit high substrate affinity relative to other enzyme-substrate pairs, PRMTs display largely lower kcat and kcat/KM values. We observe that kinetic parameters for PRMTs and arginine demethylase activity from dual-functioning lysine demethylases are statistically similar, paralleling what the broader enzyme families in which they belong reveal, and adding to the evidence in support of arginine methylation reversibility.Graphical abstract

Source: Biochimica et Biophysica Acta (BBA) Proteins and Proteomics - October 18, 2018 Category: Biochemistry Source Type: research