Allosteric control of human cystathionine β-synthase activity by a redox active disulfide bond.

ABSTRACT: Cystathionine β-synthase (CBS) is the central enzyme in the trans-sulfuration pathway that converts homocysteine to cysteine. It is also one of the three major enzymes involved in the biogenesis of H₂S. CBS is a complex protein with a modular three-domain architecture, the central domain of which contains a ²⁷²CXXC²⁷⁵ motif whose function has yet to be determined. In the present study, we demonstrated that the CXXC motif exists in oxidized and reduced states in the recombinant enzyme by mass spectroscopic analysis and a thiol labeling assay. The activity of reduced CBS is ∼2-3-fold greater than that of the oxidized enzyme, and substitution of either cysteine in CXXC motif leads to a loss of redox sensitivity. The Cys²⁷²-Cys

SUBMITTER: Niu W 

PROVIDER: S-EPMC5818181 | biostudies-literature | 2018 Feb

REPOSITORIES: biostudies-literature