Vandenbunder B, Morange M, Buc H
Proc Natl Acad Sci U S A. 1976 Aug;73(8):2696-700. doi: 10.1073/pnas.73.8.2696.
Both 1,N6-etheno-AMP and 1,N6-etheno-2'-deoxy-AMP bind at the AMP site of phosphorylase b (1,4-alpha-D-glucan:orthophosphate alpha-glucosyltransferase, EC 2.4.1.1). Etheno-AMP induces the same activation as AMP, about 30-fold higher than the activation induced by etheno-dAMP. The fluorescence of etheno-AMP and etheno-dAMP is associated with the base moiety; therefore, when free in solution, the two derivatives have identical fluorescence properties. However, when bound to phosphorylase, the fluorescence of etheno-AMP is quenched more efficiently than the fluorescence of etheno-dAMP. This difference between the fluorescence properties of the bound nucleotides suggests that a modification in the ribose ring affects the position of the adenine in the AMP site of phosphorylase b. The observed quenching may be due to a stacking interaction between an aromatic residue and the base moiety of the bound nucleotide.
1,N6-乙烯基腺苷酸（1,N6-etheno-AMP）和1,N6-乙烯基-2'-脱氧腺苷酸（1,N6-etheno-2'-deoxy-AMP）均结合于磷酸化酶b（1,4-α-D-葡聚糖：正磷酸α-葡糖基转移酶，EC 2.4.1.1）的腺苷酸位点。乙烯基腺苷酸诱导的激活作用与腺苷酸相同，比乙烯基脱氧腺苷酸诱导的激活作用高约30倍。乙烯基腺苷酸和乙烯基脱氧腺苷酸的荧光与碱基部分相关；因此，当它们在溶液中游离时，这两种衍生物具有相同的荧光特性。然而，当与磷酸化酶结合时，乙烯基腺苷酸的荧光比乙烯基脱氧腺苷酸的荧光更有效地猝灭。结合核苷酸荧光特性的这种差异表明，核糖环的修饰会影响磷酸化酶b腺苷酸位点中腺嘌呤的位置。观察到的猝灭可能是由于芳香族残基与结合核苷酸的碱基部分之间的堆积相互作用所致。
