Kinetics of inactivation of Penaeus penicillatus acid phosphatase during inhibition by N-bromosuccinimide.
In the present investigation, the inactivation by N-bromosuccinimide of acid phosphatase from penaeus penicillatus has been studied using the kinetic method of the substrate reaction during modification of enzyme activity as previously described by Tsou [(1988, Adv. Enzymemol. Related Areas Mol. Biol. 61, 381-436]. The results show that inactivation of the enzyme by N-bromosuccinimide is a slow, reversible reaction. The results also clearly show that the modification of the tryptophan residues of penaeus penicillatus acid phosphatase by high concentrations of N-bromosuccinimide led to the complete inactivation of the enzyme. The microscopic rate constants were determined for the reaction of the inactivator with the free enzyme and with the enzyme-substrate complex. Comparison of the obtained microscopic rate constants indicates that the presence of the substrate offers marked protection of the enzyme against inactivation by N-bromosuccinimide. The above results suggest that the tryptophan residue is essential for activity and may be situated at the active site of the enzyme.
Yang
P Z
PZ
Department of Biology, Xiamen University, People's Republic of China.
Chen
Q X
QX
Li
Y
Y
Chen
S L
SL
Zhou
H M
HM
D000135:Acid Phosphatase / Q000037:antagonists & inhibitors*; D000818:Animals; D001974:Bromosuccinimide / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007700:Kinetics; D033561:Penaeidae / Q000201:enzymology*
D004791:Enzyme Inhibitors; D000135:Acid Phosphatase; D001974:Bromosuccinimide