Purification and characterization of glutaredoxin (thioltransferase) from rice (Oryza sativa L.)

• Published in: Journal of biochemistry (Tokyo) Vol. 121; no. 5; pp. 842 - 848
• Main Authors: Sha, S, Minakuchi, K, Higaki, N, Sato, K, Ohtsuki, K, Kurata, A, Yoshikawa, H, Kotaru, M, Masumura, T, Ichihara, K
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01-05-1997
• Subjects: 2-hydroxyethyl disulfide; Amino Acid Sequence; antibodies; Antigen-Antibody Reactions - immunology; cysteine; dehydroascorbate reductase activity; dehydroascorbic acid; Enzyme Activation - physiology; enzyme activity; enzyme inhibitors; glutaredoxin (thioltransferase); Glutaredoxins; glutathione dehydrogenase (ascorbate); Hydrogen-Ion Concentration; inhibition; Kinetics; Molecular Sequence Data; molecular weight; Neutralization Tests; Oryza - enzymology; Oryza sativa; oxidoreductases; Oxidoreductases - analysis; Oxidoreductases - isolation & purification; Oxidoreductases - metabolism; Plant Proteins - analysis; Plant Proteins - isolation & purification; Protein Disulfide Reductase (Glutathione); purification; rice bran; seeds; sulfides (organic); sulfur proteins; thiol-disulfide interchange; thioredoxin; transferases
• ISSN: 0021-924X; 1756-2651
• DOI: 10.1093/oxfordjournals.jbchem.a021663

We purified and characterized glutaredoxin (thioltransferase), which catalyzes thiol/disulfide exchange reaction, for the first time in plants. The purification procedure employed an immunoabsorbent, antiglutaredoxin-Sepharose. Glutaredoxin was purified about 2,200-fold from rice bran and it appeared to be homogeneous on SDS-PAGE. MALDI-TOF mass spectrometry revealed that the protein has a molecular mass of 11,097.9 Da. Rice glutaredoxin consists of 105 amino acid residues, containing the tetrapeptide-Cys-Phe-Pro (Tyr)-Cys-, which constitutes the active site of Escherichia coli and mammalian glutaredoxins. Inactivation assay also indicated that cysteine residues are responsible for enzyme activity. Kinetic analyses revealed that the enzyme did not exhibit normal Michaelis-Menten kinetics. The enzyme has an optimum pH of about 8.7 with 2-hydroxyethyl disulfide as a substrate. In addition, rice glutaredoxin has dehydroascorbate reductase activity, like mammalian glutaredoxin.