title: Purification and characterization of glutaredoxin from Cryptococcus neoformans.
abstract: Glutaredoxin, also known as thioltransferase, was purified from Cryptococcus neoformans by procedures including DEAE-cellulose ion exchange chromatography, Q-Sepharose ion-exchange chromatography, and gel filtration on Sephadex G-50. Its purity was confirmed by SDS-polyacrylamide gel electrophoresis and its molecular weight was estimated to be 12,000 Da. The purified enzyme has a K(m) value of 1.03 mM with 2-hydroxyethyl disulfide as a substrate. The enzyme also utilizes L-sulfocysteine, L-cystine, and bovine serum albumin as substrates in the presence of reduced glutathione. The enzyme has K(m) values of 0.34-2.50 mM for these substrates. It was greatly activated by thiol compounds such as reduced glutathione, dithiothreitol, L-cysteine and beta-mercaptoethanol. It is partially inactivated at 60 degrees C or higher temperatures. It plays an important role in thiol-disulfide exchange in Cryptococcus neoformans.
authors.affiliation: Division of Life Sciences, College of Natural Sciences, Kangwon National University, Chunchon, Korea.
authors.forename: J H
authors.initials: JH
authors.lastname: Sa
authors.forename: K
authors.initials: K
authors.lastname: Kim
authors.forename: C J
authors.initials: CJ
authors.lastname: Lim
mesh_terms: D003455:Cryptococcus neoformans / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D005656:Fungal Proteins / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D054477:Glutaredoxins; D006358:Hot Temperature; D007526:Isoelectric Point; D007700:Kinetics; D008970:Molecular Weight; D010088:Oxidoreductases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D011490:Protein Disulfide Reductase (Glutathione); D011506:Proteins / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D013379:Substrate Specificity; D013438:Sulfhydryl Compounds
chemical_list: D005656:Fungal Proteins; D054477:Glutaredoxins; D011506:Proteins; D013438:Sulfhydryl Compounds; D010088:Oxidoreductases; D011490:Protein Disulfide Reductase (Glutathione)