Amino acid sequence of glutathione S-transferase a from guinea pig liver.

The amino acid sequence of glutathione S-transferase a from guinea pig liver was determined. Glutathione S-transferase a was composed of two identical subunits, each comprising 218 amino acid residues. The amino acid sequence of glutathione S-transferase a exhibited 73% homology with that of human glutathione S-transferase Ha, 69% with that of rat glutathione S-transferase Ya, and 68% with that of rat glutathione S-transferase Yc, which are known to belong to class Alpha. From the above result, together with previous observations on its substrate specificity, it was concluded that glutathione S-transferase a belonged to class Alpha.