Faculty Publications

Reversible Heme-Dependent Regulation of Human Cystathionine β-Synthase by a Flavoprotein Oxidoreductase

Document Type

Article

Keywords

Bioinorganic chemistry, Inhibition, Monomers, Peptides and proteins, Redox reactions

Journal/Book/Conference Title

Biochemistry

Volume

50

Issue

39

First Page

8261

Last Page

8263

Abstract

Human CBS is a PLP-dependent enzyme that clears homocysteine, gates the flow of sulfur into glutathione, and contributes to the biogenesis of H2S. The presence of a heme cofactor in CBS is enigmatic, and its conversion from the ferric– to ferrous–CO state inhibits enzyme activity. The low heme redox potential (−350 mV) has raised questions about the feasibility of the ferrous–CO state forming under physiological conditions. Herein, we provide the first evidence of reversible inhibition of CBS by CO in the presence of a human flavoprotein and NADPH. These data provide a mechanism for cross talk between two gas-signaling systems, CO and H2S, via heme-mediated allosteric regulation of CBS.

Department

Department of Chemistry and Biochemistry

Original Publication Date

8-29-2011

DOI of published version

10.1021/bi201270q

Link to Full Text

Comments?

Share

COinS