Structural and Redox Properties of the Leaderless DsbE (CcmG) Protein: Both Active-Site Cysteines of the Reduced Form Are Involved in Its Function in the Escherichia coli Periplasm
-
Qi Li
Abstract
The thiol/disulfide oxidoreductases play important roles in ensuring the correct formation of disulfide bonds, of which the DsbE protein, also called CcmG, is the one implicated in electron transfer for cytochrome c maturation in the periplasm of Escherichia coli. The soluble, Nterminally truncated DsbE was overexpressed and purified to homogeneity. Here we report the structural and redox properties of the leaderless form (DsbEL ). During the redox reaction, the protein undergoes a structural transformation resulting in a more stable reduced form, but this form shows very low reactivity in thiol/ disulfide exchange of cysteine residues and low activity in accelerating the reduction of insulin. The standard redox potential (E' 0 ) for the active thiol/ disulfide was determined to be 0.186 V; only one of the two cysteines (Cys80) was suggested to be the active residue in the redox reaction. From the aspect of biochemical properties, DsbE can be regarded as a weak reductant in the Escherichia coli periplasm. This implies that the function of DsbE in cytochrome c maturation can be ascribed to its active site cysteines and the structure of the reduced form.
Copyright © 2001 by Walter de Gruyter GmbH & Co. KG
Articles in the same Issue
- New Control of Mitochondrial Membrane Potential and ROS Formation A Hypothesis
- Brix from Xenopus laevis and Brx1p From Yeast Define a New Family of Proteins Involved in the Biogenesis of Large Ribosomal Subunits
- Mig-6 Is a Negative Regulator of the Epidermal Growth Factor Receptor Signal
- β-Carotene Inhibits Growth of Human Colon Carcinoma Cells in Vitro by Induction of Apoptosis
- Ligand-Mediated Protection against Phage Lysis as a Positive Selection Strategy for the Enrichment of Epitopes Displayed on the Surface of E. coli Cells
- Structural and Redox Properties of the Leaderless DsbE (CcmG) Protein: Both Active-Site Cysteines of the Reduced Form Are Involved in Its Function in the Escherichia coli Periplasm
- Polyphenols of Cocoa: Inhibition of Mammalian 15-Lipoxygenase
- Total Antioxidant Capacity and Nuclear DNA Damage in Keratinocytes after Exposure to H2 O2
- Recombinant Cryptic Human Fibronectinase Cleaves Actin and Myosin: Substrate Specificity and Possible Role in Muscular Dystrophy
- Rat Tripeptidyl Peptidase I: Molecular Cloning, Functional Expression, Tissue Localization and Enzymatic Characterization
- Determination of NADH in Frozen Rat Brain Sections by Laser-Induced Fluorescence
- Human -Calpain: Simple Isolation from Erythrocytes and Characterization of Autolysis Fragments
- Erratum
- Acknowledgement
- Content Index
- Author Index
- Subject Index
Articles in the same Issue
- New Control of Mitochondrial Membrane Potential and ROS Formation A Hypothesis
- Brix from Xenopus laevis and Brx1p From Yeast Define a New Family of Proteins Involved in the Biogenesis of Large Ribosomal Subunits
- Mig-6 Is a Negative Regulator of the Epidermal Growth Factor Receptor Signal
- β-Carotene Inhibits Growth of Human Colon Carcinoma Cells in Vitro by Induction of Apoptosis
- Ligand-Mediated Protection against Phage Lysis as a Positive Selection Strategy for the Enrichment of Epitopes Displayed on the Surface of E. coli Cells
- Structural and Redox Properties of the Leaderless DsbE (CcmG) Protein: Both Active-Site Cysteines of the Reduced Form Are Involved in Its Function in the Escherichia coli Periplasm
- Polyphenols of Cocoa: Inhibition of Mammalian 15-Lipoxygenase
- Total Antioxidant Capacity and Nuclear DNA Damage in Keratinocytes after Exposure to H2 O2
- Recombinant Cryptic Human Fibronectinase Cleaves Actin and Myosin: Substrate Specificity and Possible Role in Muscular Dystrophy
- Rat Tripeptidyl Peptidase I: Molecular Cloning, Functional Expression, Tissue Localization and Enzymatic Characterization
- Determination of NADH in Frozen Rat Brain Sections by Laser-Induced Fluorescence
- Human -Calpain: Simple Isolation from Erythrocytes and Characterization of Autolysis Fragments
- Erratum
- Acknowledgement
- Content Index
- Author Index
- Subject Index
