Wickramasinghe N S, Staves M P, Lacey J C
Department of Biochemistry, University of Alabama, Birmingham 35294.
Biochemistry. 1991 Mar 19;30(11):2768-72. doi: 10.1021/bi00225a005.
Biological systems synthesize proteins with an almost exclusive use of L-amino acids and virtually none of the D isomer. There has been no satisfactory explanation for the origin of this use of the L isomer. Research presented here shows that at pH 5, transfer of phenylalanine from the adenylate anhydride to ester occurs and is 95-97% efficient for the L isomer and only about 50% efficient for the D isomer. The origin of the use of the L isomer, given D-ribose nucleotides, may be based in part on this stereoselectivity.
生物系统几乎只使用L-氨基酸来合成蛋白质，几乎不使用D-异构体。对于这种L-异构体的使用起源，一直没有令人满意的解释。此处提出的研究表明，在pH值为5时，苯丙氨酸从腺苷酸酐向酯的转移会发生，L-异构体的效率为95-97%，而D-异构体的效率仅约为50%。在存在D-核糖核苷酸的情况下，L-异构体的使用起源可能部分基于这种立体选择性。
