Incorrect Question 2 0/1 pts xt Uncatalyzed hydrolysis Serine protease-catalyzed
ID: 265469 • Letter: I
Question
Incorrect Question 2 0/1 pts xt Uncatalyzed hydrolysis Serine protease-catalyzed hydrolysis E + H20 C D Progress of Reaction This is a reaction coordinate for the hydrolysis of a peptide bond without catalysis, and by a serine protease. If the decrease in free energy (energy well) associated with position A is binding of substrate, what is the energy well at position B? formation of the tetrahedral intermediate hydrolysis of the acyl enzyme formation of the oxyanion hole release of first protein product formation of the acyl enzyme intermediateExplanation / Answer
Substrate binding in serine proteases is followed by tetrahedral intermediate formation. It is formed by the nucleophilic attack of OH-group of serine on the C of the amide bond in the polypeptide. The peptide is coordinated with His-Asp by weak interaction and a covalent bond with catalytic serine. This form is stable than the substrate-bound form of the enzyme. So, B is a tetrahedral intermediate while A is just substrate-bound form without any interaction of catalytic residues of the enzyme with the substrate