creators_name: Garg, Saurabh K
creators_name: Suhail Alam, Md
creators_name: Soni, Vishal
creators_name: Radha Kishan, K V
creators_name: Agrawal, Pushpa
type: article
datestamp: 2012-01-09 04:25:16
lastmod: 2012-01-09 04:25:16
metadata_visibility: show
title: Characterization of Mycobacterium tuberculosis WhiB1/Rv3219 as a protein disulfide reductase.
ispublished: pub
subjects: QR
full_text_status: restricted
keywords: whiB1; M. tuberculosis; Thioredoxin; Protein disulfide reductase; Intramolecular disulfide bond; C–X–X–C motif
note: Copyright of this article belongs to Elsevier Science.
abstract: WhiB family of protein is emerging as one of the most fascinating group and is implicated in stress response as well as pathogenesis via their involvement in diverse cellular processes. Surprisingly, available in vivo data indicate an organism specific physiological role for each of these proteins. The WhiB proteins have four conserved cysteine residues where two of them are present in a C-X-X-C motif. In thioredoxins and similar proteins, this motif works as an active site and confers thiol-disulfide oxidoreductase activity to the protein. The recombinant WhiB1/Rv3219 was purified in a single step from Escherichia coli using Ni(2+)-NTA affinity chromatography and was found to exist as a homodimer. Mass spectrometry of WhiB1 shows that the four cysteine residues form two intramolecular disulfide bonds. Using intrinsic tryptophan fluorescence as a measure of redox state, the redox potential of WhiB1 was calculated as -236+/-2mV, which corresponds to the redox potential of many cytoplasmic thioredoxin-like proteins. WhiB1 catalyzed the reduction of insulin disulfide thus clearly demonstrating that it functions as a protein disulfide reductase. Present study for the first time suggests that WhiB1 may be a part of the redox network of Mycobacterium tuberculosis through its involvement in thiol-disulfide exchange with other cellular proteins.
date: 2007-04
date_type: published
publication: Protein expression and purification
volume: 52
number: 2
publisher: Elsevier Science
pagerange: 422-32
refereed: TRUE
issn: 1046-5928
official_url: http://www.sciencedirect.com/science/article/pii/S1046592806003305
related_url_url: http://www.sciencedirect.com/science/article/pii/S1046592806003305
related_url_type: pub
citation:   Garg, Saurabh K and Suhail Alam, Md and Soni, Vishal and Radha Kishan, K V and Agrawal, Pushpa  (2007) Characterization of Mycobacterium tuberculosis WhiB1/Rv3219 as a protein disulfide reductase.  Protein expression and purification, 52 (2).  pp. 422-32.  ISSN 1046-5928     
document_url: http://crdd.osdd.net/open/130/1/pushpa2007.1.pdf