Which of the following would result in the greatest decrease in function of the catalytic triad found in serine proteases?
A)Mutation to Ser,Cys,Asp
B)Mutation to Ser,His,Asp
C)Mutation to Cys,His,Asp
D)Mutation to Ser,His,Glu
E)Mutation to Cys,His,Glu

Question

Quizplus · Accepted Answer

The catalytic triad of serine proteases involves Serine (nucleophile), Histidine (base), and Aspartic acid (acid). Cysteine cannot substitute for serine as the nucleophile because it cannot form a strong hydrogen bond with the histidine, making the histidine less effective as a base. Glutamic acid cannot substitute for aspartic acid as the acid because it is too far away from the other two residues. Therefore, the mutation to Cys, His, and Asp would result in the greatest decrease in function of the catalytic triad.

Which of the Following Would Result in the Greatest Decrease