Shimojo T, Akino T, Miura Y, Schroepfer G J
J Biol Chem. 1976 Jul 25;251(14):4448-7.
D-erythro-(2S, 3R)-Sphinganine 1-phosphate was incubated with rat liver microsomes in the presence of tritiated water. [3H]Ethanolamine 1-phosphate was isolated and converted, through a combination of enzymatic and chemical reactions, to [3H]glycine. The labeled glycine was incubated with D-amino acid oxidase, an enzyme which, in the catalysis of the conversion of glycine to glyoxylic acid, specifically removes the hydrogen in the S configuration at carbon atom 2 of glycine. Essentially complete retention of the labeled hydrogen occurred upon conversion to glyoxylic acid. The combined results indicate that the conversion of D-erythro-(2S,3R)-sphinganine 1-phosphate to palmitaldehyde and ethanolamine 1-phosphate, catalyzed by sphinganine-1-phosphate lyase of rat liver microsomes, proceeds with the stereospecific incorporation of 1 atom of solvent hydrogen into the R configuration of ethanolamine 1-phosphate.
在含有氚化水的情况下，将D-赤藓糖型-（2S，3R）-鞘氨醇1-磷酸与大鼠肝脏微粒体一起温育。分离出[3H]乙醇胺1-磷酸，并通过酶促反应和化学反应的组合将其转化为[3H]甘氨酸。将标记的甘氨酸与D-氨基酸氧化酶一起温育，该酶在催化甘氨酸转化为乙醛酸的过程中，特异性地去除甘氨酸碳原子2上S构型的氢。转化为乙醛酸后，标记的氢基本完全保留。综合结果表明，大鼠肝脏微粒体的鞘氨醇-1-磷酸裂解酶催化D-赤藓糖型-（2S，3R）-鞘氨醇1-磷酸转化为棕榈醛和乙醇胺1-磷酸的过程中，有1个溶剂氢原子立体定向地掺入乙醇胺1-磷酸的R构型中。
