Question

2. Penicillin acts as a suicide substrate. Which
one of the following steps of catalysis does
a suicide inhibitor affect?
ki
K₂
k;
E+S[E.S)
[E.P]
(E+P]
L
1. ki
3. k3
2. k2
4. ke​

Answer 1

ANSWER: On binding to the transpeptidase, the serine residue at the active site attacks the carbonyl carbon atom of the lactam ring to form the penicilloyl-serine derivative (Figure 8.31). Because the peptidase participates in its own inactivation, penicillin acts as a suicide inhibitor.