Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-24T12:00:23.293Z Has data issue: false hasContentIssue false

The oxidation produced by hydrogen peroxide on Ca-ATP-G-actin

Published online by Cambridge University Press:  05 October 2000

ALDO MILZANI
Affiliation:
Laboratory of Biochemistry and Biophysics of Cytoskeleton, Department of Biology, University of Milan, via Celoria 26, I-20133 Milan, Italy
RANIERI ROSSI
Affiliation:
Pharmacology Section, Institute for Mental and Nervous Diseases, University of Siena, via A. Moro 4, I-53100 Siena, Italy
PAOLO DI SIMPLICIO
Affiliation:
Pharmacology Section, Institute for Mental and Nervous Diseases, University of Siena, via A. Moro 4, I-53100 Siena, Italy
DANIELA GIUSTARINI
Affiliation:
Pharmacology Section, Institute for Mental and Nervous Diseases, University of Siena, via A. Moro 4, I-53100 Siena, Italy
ROBERTO COLOMBO
Affiliation:
Laboratory of Biochemistry and Biophysics of Cytoskeleton, Department of Biology, University of Milan, via Celoria 26, I-20133 Milan, Italy
ISABELLA DALLEDONNE
Affiliation:
Laboratory of Biochemistry and Biophysics of Cytoskeleton, Department of Biology, University of Milan, via Celoria 26, I-20133 Milan, Italy
Get access

Abstract

We report here that in vitro exposure of monomeric actin to hydrogen peroxide leads to a conversion of 6 of the 16 methionine residues to methionine sulfoxide residues. Although the initial effect of H2O2 on actin is the oxidation of Cys374, we have found that Met44, Met47, Met176, Met190, Met269, and Met355 are the other sites of the oxidative modification. Met44 and Met47 are the methionyl sites first oxidized. The methionine residues that are oxidized are not simply related to their accessibility to the external medium and are found in all four subdomains of actin. The conformations of subdomain 1, a region critical for the functional binding of different actin-binding proteins, and subdomain 2, which plays important roles in the polymerization process and stabilization of the actin filament, are changed upon oxidation. The conformational changes are deduced from the increased exposure of hydrophobic residues, which correlates with methionine sulfoxide formation, from the perturbations in tryptophan fluorescence, and from the decreased susceptibility to limited proteolysis of oxidized actin.

Type
Research Article
Copyright
2000 The Protein Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)