Porcine glutathione transferase Alpha 2-2 is a human GST A3-3 analogue that catalyses steroid double-bond isomerization

作者：Fedulova Natalia; Raffalli Mathieu Francoise; Mannervik Bengt^*

来源：Biochemical Journal, 2010, 431: 159-167.

DOI：10.1042/BJ20100839

• Delta(5)-androstene-3
• 17-dione
• androstenedione
• double-bond isomerization
• glutathione transferase Alpha 2-2 (GST A2-2)
• steroidogenesis
• tributyltin

A primary role of GSTs (glutathione transferases) is detoxication of electrophilic compounds. In addition to this protective function, hGST (human GST) A3-3, a member of the Alpha class of soluble GSTs, has prominent steroid double-bond isomerase activity. The isomerase reaction is an obligatory step in the biosynthesis of steroid hormones, indicating a special role of hGST A3-3 in steroidogenic tissues. An analogous GST with high steroid isomerase activity has so far not been found in any other biological species. In the present study, we characterized a Sus scrofa (pig) enzyme, pGST A2-2, displaying high steroid isomerase activity. High levels of pGST A2-2 expression were found in ovary, testis and liver. In its functional properties, other than steroid isomerization, pGST A2-2 was most similar to hGST A3-3. The properties of the novel porcine enzyme lend support to the notion that particular GSTs play an important role in steroidogenesis.

• 出版日期2010-10-1