Otto P, Ladik J, Szent-Györgyi A
Proc Natl Acad Sci U S A. 1979 Aug;76(8):3849-51. doi: 10.1073/pnas.76.8.3849.
Ab initio self-consistent field calculations for neutral and cationic ascorbic acid and model compounds have been performed. Furthermore, the bicyclic addition products of alpha-hydroxytetronic acid with methylglyoxal and with the Schiff base formed between methylglyoxal and methylamine have been calculated, again in their neutral and cationic forms, respectively. The results indicate that the investigated cations can act as strong electron acceptors. With the help of space-filling molecular models it has been demonstrated that such conformations of the Schiff base formed between the primary amino group of lysine side chains in proteins and the ascorbic acid methylglyoxal acetal are possible in which the lactone carbonyl group comes near to the N atoms of the peptide groups, so that charge can be transferred between these subunits.
已对中性和阳离子形式的抗坏血酸及模型化合物进行了从头算自洽场计算。此外，还分别计算了α - 羟基丁烯二酸与甲基乙二醛以及甲基乙二醛与甲胺形成的席夫碱的双环加成产物的中性和阳离子形式。结果表明，所研究的阳离子可作为强电子受体。借助空间填充分子模型已证明，蛋白质中赖氨酸侧链的伯氨基与抗坏血酸甲基乙二醛缩醛形成的席夫碱可能具有这样的构象，即内酯羰基靠近肽基团的N原子，从而使电荷能够在这些亚基之间转移。
