Kinetics and reaction mechanism of potassium-activated aldehyde dehydrogenase from Saccharomyces cerevisiae.
Data from steady-state kinetic analysis of yeast K+-activated aldehyde dehydrogenase are consistent with a ternary complex mechanism. Evidence from alternative substrate analysis and product-inhibition studies supports an ordered sequence of substrate binding in which NAD+ is the leading substrate. A preincubation requirement for NAD+ for maximum activity is also consistent with the importance of a binary enzyme-NAD+ complex. Dissociation constant for enzyme-NAD+ complex determined kinetically is in reasonable agreement with that determined by direct binding. The order of substrate addition proposed here differs from that proposed for a yeast aldehyde dehydrogenase previously reported. Different methods of purification produced an enzyme that showed similar kinetic characteristics to those reported here.
D000445:Aldehyde Oxidoreductases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D007700:Kinetics; D009243:NAD; D009249:NADP; D011188:Potassium / Q000494:pharmacology; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000201:enzymology*
D009243:NAD; D009249:NADP; D000445:Aldehyde Oxidoreductases; D011188:Potassium