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BioMed Research International
Volume 2014, Article ID 246871, 6 pages
http://dx.doi.org/10.1155/2014/246871
Research Article

Cloning, Expression, Purification, and Characterization of Glutaredoxin from Antarctic Sea-Ice Bacterium Pseudoalteromonas sp. AN178

1School of Marine and Technology, Harbin Institute of Technology, Weihai 264209, China
2Shandong Provincial Engineering Technology Research Center of Marine Health Food (Taixiang Group), Rongcheng 264300, China
3Shandong Provincial Key Laboratory of Processing Technology of Frozen Prepared Food (Taixiang Group), Rongcheng 264300, China

Received 28 April 2014; Revised 22 June 2014; Accepted 24 June 2014; Published 7 July 2014

Academic Editor: Bo Zuo

Copyright © 2014 Quanfu Wang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Glutaredoxins (Grxs) are small ubiquitous redox enzymes that catalyze glutathione-dependent reactions to reduce protein disulfide. In this study, a full-length Grx gene (PsGrx) with 270 nucleotides was isolated from Antarctic sea-ice bacterium Pseudoalteromonas sp. AN178. It encoded deduced 89 amino acid residues with the molecular weight 9.8 kDa. Sequence analysis of the amino acid sequence revealed the catalytic motif CPYC. Recombinant PsGrx (rPsGrx) stably expressed in E. coli BL21 was purified to apparent homogeneity by Ni-affinity chromatography. rPsGrx exhibited optimal activity at 30°C and pH 8.0 and showed 25.5% of the activity at 0°C. It retained 65.0% of activity after incubation at 40°C for 20 min and still exhibited 37.0% activity in 1.0 M NaCl. These results indicated that rPsGrx was a typical cold active protein with low thermostability.