Redox regulation and trapping sulphenic acid in the peroxide sensitive human mitochondrial branched chain aminotransferase

Coles, Steven; Hutson, Susan M.; Poole, Leslie B.; Conway, Myra E.

Abstract

The human branched chain aminotransferase enzymes are key regulators of glutamate metabolism in the brain and are among a growing number of redox-sensitive proteins. Studies that use thiol-specific reagents and electrospray ionization mass spectrometry demonstrate that the mitochondrial BCAT enzyme has a redox-active CXXC center, which on oxidation forms a disulfide bond (RSSR), via a cysteine sulfenic acid intermediate. Mechanistic details of this redox regulation were revealed by the use of mass spectrometry and dimedone modification. We discovered that the thiol group at position C315 of the CXXC motif acts a redox sensor, whereas the thiol group at position C318 permits reversible regulation by forming an intrasubunit disulphide bond. Because of their roles in redox regulation and catalysis, there is a growing interest in cysteine sulphenic acids. Therefore, development of chemical tags/methods to trap these transient intermediates is of immense importance. © 2008 Humana Press, a part of Springer Science+Business Media, LLC.

• Journal Article Type: Article
• Publication Date: Dec 1, 2008
• Journal: Methods in Molecular Biology
• Print ISSN: 1064-3745
• Publisher: Humana Press
• Peer Reviewed: Not Peer Reviewed
• Volume: 476
• Pages: 139-152
• Series Title: Methods in Molecular Biology
• DOI: https://doi.org/10.1007/978-1-59745-129-1_10
• Keywords: molecular biology, redox-mediated signal transduction, sulphenic acid, human mitochondrial branched chaim aminotransferase
• Public URL: https://uwe-repository.worktribe.com/output/1008215
• Publisher URL: http://www.springerprotocols.com/BookToc/doi/10.1007/978-1-59745-129-1