Cystathionine-d4 is intended for use as an internal standard for the quantification of cystathionine by GC- or LC-MS. Cystathionine is an intermediate in the biosynthesis of cysteine that is composed of homocysteine and serine.1,2 It has four potential isomers, L-cystathionine, D-cystathionine, L-allocystathionine, and D-allocystathionine.3 Dietary administration of L-allocystathionine (0.74%) or the naturally occurring L-cystathionine (0.74%) substitute for cystine and increase the body weight of growing rats.
1.Steegborn, C., Clausen, T., Sondermann, P., et al.Kinetics and inhibition of recombinant human cystathionine γ-lyase. Toward the rational control of transsulfurationJ. Biol. Chem.274(18)12675-12684(1999) 2.Finkelstein, J.D.The metabolism of homocysteine: Pathways and regulationEur. J. Pediatr.157(Suppl 2)S40-S44(1998) 3.Anslow, W.P., Jr., Simmonds, S., and Du Vigneaud, V.The synthesis of the isomers of cystathionine and a study of their availability in sulfur metabolismJ. Biol. Chem.166(1)35-45(1946)