Askew S C, Butler A R, Flitney F W, Kemp G D, Megson I L
School of Chemistry, University of St. Andrews, Fife, Scotland, U.K.
Bioorg Med Chem. 1995 Jan;3(1):1-9. doi: 10.1016/0968-0896(94)00139-t.
The chemistries of S-nitroso-DL-penicillamine (SNAP) and S-nitrosoglutathione (GSNO) in relation to their ability to relax vascular smooth muscle and prevent platelet aggregation have been investigated. Metal ion catalysis greatly accelerates the decomposition of SNAP, but has little effect on GSNO. Instead, NO release from GSNO is effected either by NO transfer to a free thiol (e.g. cysteine), or by enzymatic cleavage of the glutamyl-cystyl peptide bond. In both cases the resulting nitrosothiol (i.e. S-nitrosocysteine and S-nitrosocystylglycine, respectively) is susceptible to metal ion catalysed NO release. We conclude that transnitrosation or enzymatic cleavage are obligatory steps in the mechanism of NO release from GSNO, whereas SNAP needs only the presence of metal ions to effect this process. The different modes of NO production may go some way towards explaining the different physiological effectiveness of these S-nitrosothiols as vasodilators and inhibitors of platelet aggregation.
已对S-亚硝基-DL-青霉胺（SNAP）和S-亚硝基谷胱甘肽（GSNO）的化学性质与其舒张血管平滑肌及防止血小板聚集能力之间的关系进行了研究。金属离子催化极大地加速了SNAP的分解，但对GSNO影响很小。相反，GSNO释放NO是通过NO转移至游离硫醇（如半胱氨酸）或通过谷氨酰-半胱氨酰肽键的酶促裂解来实现的。在这两种情况下，生成的亚硝基硫醇（即分别为S-亚硝基半胱氨酸和S-亚硝基半胱氨酰甘氨酸）易受金属离子催化的NO释放影响。我们得出结论，转亚硝化作用或酶促裂解是GSNO释放NO机制中的必要步骤，而SNAP仅需金属离子的存在即可实现此过程。NO产生的不同模式可能在一定程度上解释了这些亚硝基硫醇作为血管舒张剂和血小板聚集抑制剂的不同生理效能。
