Purification and some properties of bovine liver cytosol thioltransferase.
A cytosol thioltransferase was purified 37,000-fold from bovine liver by essentially the same procedure as reported for rat liver enzyme by Axelsson et al. [1978) Biochemistry 17, 2978-2984). The purified enzyme appears to be homogeneous on sodium dodecyl sulfate (SDS)-gel electrophoresis and has a molecular weight (Mr) of 11,000, an isoelectric point (pI) of 8.1, and an optimum pH with S-sulfocysteine and GSH as substrates of 8.5. It is specific for disulfides including L-cystine, S-sulfocysteine, ribonuclease A, trypsin, soybean kunitz trypsin inhibitor, soybean Bowman Birk trypsin inhibitor and insulin, and converts Bowman Birk trypsin inhibitor to an inactive form. The enzyme does not act as a protein : disulfide isomerase, as measured by reactivation of "scramble" ribonuclease and Kunitz soybean trypsin inhibitor. Thioltransferase activity was found in cytosol of various bovine tissues.
D000818:Animals; D002417:Cattle; D003600:Cytosol / Q000201:enzymology; D054477:Glutaredoxins; D005978:Glutathione / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D010088:Oxidoreductases / Q000302:isolation & purification* / Q000378:metabolism; D011490:Protein Disulfide Reductase (Glutathione); D013379:Substrate Specificity
D054477:Glutaredoxins; D010088:Oxidoreductases; D011490:Protein Disulfide Reductase (Glutathione); D005978:Glutathione