Skip to Content
Medical Term:

cystathionine ?-lyase

Pronunciation: sis'ta-thi'o-nen li'as


A liver enzyme, requiring pyridoxal phosphate as coenzyme, which catalyzes the hydrolysis of l-cystathionine to l-cysteine and 2-ketobutyrate, releasing NH3; also catalyzes formation of 2-ketobutyrate from l-homoserine, of pyruvate (and NH3 and H2S) from l-cysteine, and of thiocysteine, pyruvate, and NH3 from cystine. A deficiency of this enzyme results in cystathioninuria. It catalyzes a step in methionine catabolism and in cysteine biosynthesis.

Synonym(s): cystathionase, cysteine desulfhydrase, cystine desulfhydrase, ?-cystathionase, homoserine deaminase, homoserine dehydratase

See Also: cystathionine ß-lyase

© Copyright 2017 Wolters Kluwer. All Rights Reserved. Review Date: Sep 19, 2016.