Glutathione insulin transhydrogenase

This enzyme [EC 1.8.4.2], also known as glutathione insulin transhydrogenase and insulin reductase, catalyzes the reaction of two glutathione with a disulfide bond in a protein to produce glutathione disulfide and a protein with two new thiol groups. The enzyme can reduce insulin and a number of other proteins. 

Glutathione-insulin transhydrogenase, 130 Glutathione peroxidase, 130 Glutathione protein disulfide oxidoreduo-tase, 130... 

Liver and kidney primarily, but other tissues as well, contain a rather specific enzyme glutathione-insulin transhydrogenase, which in the presence of glutathione catalyzes the cleavage of the a from the P chain as a result of the reduction of the S-S bond that holds the two chains together. Proteolytic enzymes, then, degrade most of the reduced chain, except perhaps for a small amount of the P chain, which may escape into the blood and bind to other molecules. 

Ansorge, S., Bohley, P., Kirschke, H., Langner, J., Wiederanders, B., and Hanson, H., 1973, Metabolism of insulin and glucagon. Glutathione-insulin transhydrogenase from microsomes of rat liver, Eur. J. Biochem. 32 27. 

Varandani, P. T., 1974, Insulin degradation in insulinoma Evidence for the occurrence of an active form of glutathione-insulin transhydrogenase and for the absence of insulin A and B chains degrading proteases, Biochem. Biophys. Res. Commun. 60 1119. 

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