MCB 354 Lecture Notes - Lecture 11: Table Tennis, Serine Protease, Oxyanion Hole
Document Summary
Most enzymes catalyze rxns with more than one substrate. Many rxns transfer a functional group from one substrate to the other. In general: a+b p+q where there are 2 substrates and 2 products and the reactants may bind or products my release in a specific order. You can vary a and b separately to determine vmax and km. Sequential: both substrates bind the enzyme before any product is released. Basic residues in the enzyme active site stabilize phosphates (charge shielding) in the ts. Active site is buried and protected from water so that the phosphoryl transfer to glucose occurs instead of hydrolysis. Ping-pong: a product is released before the second substrate is bound. Chymotrypsin is a serine protease family member and cleaves peptide bonds at the c terminus of aromatic aas. It is made as a zymogen that is activated by trypsin in the digestive tract. It enhances the rate of peptide hydrolysis by > 10 9 and the reaction: