Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:4.2.1.22 (
cystathionine beta-synthase
)
965
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
H2S is produced from cysteine by
cystathionine beta-synthase
(
CBS
) in the brain and functions as a neuromodulator. Although the production of H2S is regulated by Ca2+ and calmodulin in response to neuronal excitation, little is known about the molecular mechanism for the regulation in
CBS
activity. Here we show that four cysteine residues of
CBS
are involved in the regulation of its activity in the presence of Ca2+ and calmodulin.
Sodium nitroprusside
(SNP), a modifying agent for cysteine residues, enhances
CBS
activity, whereas N-ethylmaleimide, an alkylating agent for cysteine residues, completely abolished the effect of SNP. Site-directed mutagenesis of the 13 cysteine residues of
CBS
identified four cysteine residues that are involved in the regulation of
CBS
activity by SNP, and two of the four residues are involved in the regulation of the basal
CBS
activity. The enhancement of
CBS
activity by SNP is independent of nitric oxide production. In the presence of Staphylococcus aureus alpha-hemolysin, which permeabilizes the cell membrane, exogenously applied SNP enhances the activity of
CBS
in intact cells. The present study demonstrates a novel mechanism for the regulation of
CBS
activity and provides a possible therapeutic application of SNP for the diseases in which
CBS
activity is deficient.
...
PMID:A novel enhancing mechanism for hydrogen sulfide-producing activity of cystathionine beta-synthase. 1221 17
