胱硫醚 （Cystathionine）是一种半胱氨酸合成代谢的中间产物。

在氨基酸代谢中，胱硫醚由高半胱氨酸和丝氨酸通过胱硫醚β-裂合酶合成，再由胱硫醚γ-裂合酶裂解为半胱氨酸和α-丁酮酸。

尿液中胱硫醚过多被称为cystathioninuria症。

医学导航：遗传代谢缺陷

代谢、k,c/g/r/p/y/i,f/h/s/l/o/e,a/u,n,m

k,cgrp/y/i,f/h/s/l/o/e,au,n,m,人名体征

药物(A16/C10)、中间产物(k,c/g/r/p/y/i,f/h/s/o/e,a/u,n,m)

Cystathionine is an intermediate in the synthesis of cysteine.

An excess in the urine is called cystathioninuria.

Biosynthetically, cystathionineis generated from homocysteine and serine by cystathionine beta synthase (upper reaction in the diagram below). It is then cleaved into cysteine and α-ketobutyrate by cystathionine gamma-lyase (lower reaction).