大鼠脑中（+）-S-腺苷-L-甲硫氨酸的存在及其对苯乙醇胺N-甲基转移酶活性的影响

The presence of (+)-S-adenosyl-L-methionine in the rat brain and its lack of effect on phenylethanolamine N-methyltransferase activity.

作者信息

Beaudouin C, Haurat G, Laffitte J A, Renaud B

机构信息

Laboratoire de Neuropharmacologie, Faculté de Pharmacie, Université Claude Bernard, Lyon, France.

出版信息

J Neurochem. 1993 Sep;61(3):928-35. doi: 10.1111/j.1471-4159.1993.tb03604.x.

DOI:10.1111/j.1471-4159.1993.tb03604.x

PMID:8360691

Abstract

(+)-S-Adenosyl-L-methionine [(+)-SAM] was isolated from rat brain and was quantified by HPLC followed by UV spectrophotometric measurements and by 1H-NMR. Its estimated ratio in brain is 3% of total SAM. Because of its commercial unavailability, (+)-SAM was also prepared from chemically synthesized SAM by separation of the two diastereoisomers on a preparative reverse-phase Nucleosil C8 column. The (+) diastereoisomer thus obtained was then assayed in vitro both as an inhibitor and a substrate of phenylethanolamine N-methyltransferase. Enzymatic activity was measured by HPLC analysis. It was shown that (+)-SAM has no effect on phenylethanolamine N-methyltransferase activity; therefore, it is unlikely that (+)-SAM plays any possible role in regulation of adrenaline synthesis in the brain.

摘要

从大鼠脑中分离出(+)-S-腺苷-L-甲硫氨酸[(+)-SAM]，并通过高效液相色谱（HPLC）结合紫外分光光度法测量和1H-核磁共振（1H-NMR）对其进行定量。其在脑中的估计比例为总SAM的3%。由于无法从商业途径获得(+)-SAM，因此也通过在制备型反相Nucleosil C8柱上分离两种非对映异构体，从化学合成的SAM制备(+)-SAM。然后，将由此获得的(+)非对映异构体作为苯乙醇胺N-甲基转移酶的抑制剂和底物进行体外测定。通过HPLC分析测量酶活性。结果表明，(+)-SAM对苯乙醇胺N-甲基转移酶活性没有影响；因此，(+)-SAM在脑中肾上腺素合成的调节中不太可能发挥任何作用。