title: Novel highly active recombinant glutaredoxin from Chlorella sorokiniana T-89.
abstract: Glutaredoxin (Grx) is a thiol/disulfide oxidoreductase that maintains the cellular thiol/disulfide ratio. A 321 bp cDNA fragment encoding a putative Grx (named CsT-89Grx) was cloned from heat-tolerant Chlorella sorokiniana T-89 and expressed in an Escherichia coli system. The sequence analysis of CsT-89Grx and site-directed mutations showed that the putative active site within the CPYC motif belonged to the dithiol superfamily. The biochemical property analyses showed that the optimal pH and temperature of CsT-89Grx are pH 8.5 and 50 °C, respectively. The activity of CsT-89Grx showed high thermal stability (retained 70% activity at 80 °C for 30 min) and broad pH stability (retained over 70% activity for 1 h) ranging from pH 3 to 11. The kinetic parameter kcat/Km was 20,982 min(-1) mM(-1), which suggested that CsT-89Grx exhibited the highest catalytic efficiency in reducing the disulfide bond among all the Grx reported in the related literature and is therefore potentially useful for industrial applications.
authors.affiliation: Department of Food Science and Biotechnology, National Chung Hsing University , Taichung, Taiwan.
authors.forename: Hsu-Han
authors.initials: HH
authors.lastname: Chuang
authors.forename: Chu-Ying
authors.initials: CY
authors.lastname: Cheng
authors.forename: Yu-Ting
authors.initials: YT
authors.lastname: Chen
authors.forename: Jei-Fu
authors.initials: JF
authors.lastname: Shaw
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D020134:Catalytic Domain; D002708:Chlorella / Q000201:enzymology* / Q000235:genetics*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry; D004795:Enzyme Stability; D004926:Escherichia coli; D015870:Gene Expression; D054477:Glutaredoxins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007259:Infrared Rays; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011994:Recombinant Proteins; D016415:Sequence Alignment
chemical_list: D018076:DNA, Complementary; D054477:Glutaredoxins; D011994:Recombinant Proteins