Histidine an active site amino acid of glutathione S-transferase GST from the larvae of the diamondback moth

Balabaskaran S., . and Uma Devi M.P., . (1990) Histidine an active site amino acid of glutathione S-transferase GST from the larvae of the diamondback moth. [Proceedings Paper]

The requirement of a functional histidine residue for the catalytic activity of Diamondback moth Glutathione S Transferase was studied. By measuring the pH dependence of the enzyme while varying substrate concentrations pKa values of 6.85 and 7.20 were obtained suggesting the probable presence of histidine at the active site. Reaction of GST with diethylpyrocarbonate DEPC lead to an almost complete loss of enzyme activity. This inactivation could be partially reversed by treatment with hydroxylamine. Glutathione GSH afforded partial protection to the enzyme from inactivation by DEPC. The present study provides convincing evidence that a functional histidyl residue is necessary for the catalytic activity of the enzyme.

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Abstract

The requirement of a functional histidine residue for the catalytic activity of Diamondback moth Glutathione S Transferase was studied. By measuring the pH dependence of the enzyme while varying substrate concentrations pKa values of 6.85 and 7.20 were obtained suggesting the probable presence of histidine at the active site. Reaction of GST with diethylpyrocarbonate DEPC lead to an almost complete loss of enzyme activity. This inactivation could be partially reversed by treatment with hydroxylamine. Glutathione GSH afforded partial protection to the enzyme from inactivation by DEPC. The present study provides convincing evidence that a functional histidyl residue is necessary for the catalytic activity of the enzyme.

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Item Type:	Proceedings Paper
Additional Information:	3 graphs; 1 table; 3 ref.
AGROVOC Term:	PLUTELLA XYLOSTELLA
AGROVOC Term:	HISTIDINA
AGROVOC Term:	TRANSFERASAS/ ACTIVIDAD ENZIMATICA
AGROVOC Term:	PH
AGROVOC Term:	PREPARACION ENZIMATICA
Geographical Term:	MALAYSIA
Depositing User:	Ms. Norfaezah Khomsan
Last Modified:	24 Apr 2025 05:26
URI:	http://webagris.upm.edu.my/id/eprint/14773

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