Purification and characterization of a novel glutathione S-transferase from Asaphis dichotoma.
An isoenzyme of glutathione S-transferase (adGST) was purified from liver intestine of the seashell (Asaphis dichotoma) by GST-Sepharose 4B affinity chromatography followed by reverse-phase HPLC. The enzyme has a pI value of 4.6 and is composed of two subunits each with a molecular weight of 23kDa. It exhibits different catalytic activities toward the substrates 1-chloro-2,4-dinitrobenzene, 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole, ethacrynic acid, and p-nitrophenyl acetate and, fascinatingly, shows high activity toward CDNB. The amino acid composition of adGST was determined and found to be very similar to the Sloane squid GSTs. N-terminal analysis of the first 15 residues of adGST revealed that it has 73% sequence identity with the pig roundworm GSTs. The adGST shows characteristics similar to those of class sigma GSTs, as was indicated by its substrate specificity, N-terminal amino acid sequence, and amino acid composition.
Yang
Hai ling
Hl
Department of Biochemistry and Molecular Biology, College of Life Sciences, Peking University, Beijing 100871, China.
Nie
Li jia
Lj
Zhu
Sheng geng
Sg
Zhou
Xian wan
Xw
D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D004137:Dinitrochlorobenzene / Q000378:metabolism; D005982:Glutathione Transferase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D007422:Intestines / Q000201:enzymology; D008099:Liver / Q000201:enzymology; D008969:Molecular Sequence Data; D008974:Mollusca / Q000201:enzymology*; D010446:Peptide Fragments / Q000737:chemistry; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
D004137:Dinitrochlorobenzene; D010446:Peptide Fragments; D005982:Glutathione Transferase