Highly efficient production of l-cystathionine from O-succinyl-l-homoserine and l-cysteine by Streptomyces cystathionine γ-lyase

Utilizing the γ-replacement reaction of Streptomyces cystathionine γ-lyase (EC 4.4.1.1.), an efficient production method for l-cystathionine has been established. Under optimal conditions, 50 mM l-cystathionine was synthesized from 50 mM O-succinyl-l-homoserine and 50 mM l-cysteine, added in four stages to the reaction mixture, with a substrate conversion rate of 100%. This productivity (11 gl^-1 of reaction mixture) is about 3.5 times higher than that with l-homoserine and l-cysteine as substrates.