Glutathione S-transferase from the Icelandic scallop (Chlamys islandica): isolation and partial characterization.
Glutathione S-transferase from the digestive gland of the cold-adapted marine bivalve Icelandic scallop was purified to apparent homogeneity by single GSTrap chromatography. The enzyme appeared to be a homodimer with subunit M(r) 22,000 having an optimum catalytic activity at pH 6.5-7. Enzymatic analysis of scallop GST using the substrates 1-chloro-2,4-dinitrobenzene (CDNB) and glutathione resulted in apparent values for K(m)(GST) and K(m)(CDNB) of 0.3 mM and 0.4 mM, respectively. The scallop GST lost activity faster than porcine GST when exposed to increased temperatures, but both enzymes needed 10 min incubation at 60 degrees C for complete inactivation. A partial coding sequence was identified in cDNA synthesised from digestive gland mRNA. Comparison to known sequences indicates that the gene product is a glutathione S-transferase, and the predicted Icelandic scallop GST protein scores 40% sequence identity and 60% sequence similarity to mu-class proteins.
Myrnes
Bjørnar
B
Marine Biotechnology and Fish Health, Norwegian Institute of Fisheries and Aquaculture, P. O. Box 6122, N-9291 Tromsø, Norway. bjornar.myrnes@fiskeriforskning.no
Nilsen
Inge W
IW
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary / Q000235:genetics; D041981:Gastrointestinal Tract / Q000201:enzymology; D005982:Glutathione Transferase / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D049897:Pectinidae / Q000201:enzymology* / Q000235:genetics; D016415:Sequence Alignment
D018076:DNA, Complementary; D005982:Glutathione Transferase