DeBlassio J L, deLong M A, Glufke U, Kulathila R, Merkler K A, Vederas J C, Merkler D J
Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282, USA.
Arch Biochem Biophys. 2000 Nov 1;383(1):46-55. doi: 10.1006/abbi.2000.2047.
Bifunctional peptidylglycine alpha-amidating monooxygenase (PAM) catalyzes the copper-, ascorbate-, and O2-dependent cleavage of C-terminal glycine-extended peptides, N-acylglycines, and the bile acid glycine conjugates to the corresponding amides and glyoxylate. Two known metabolites of aspirin, salicyluric acid and gentisuric acid, are also substrates for PAM, leading to the formation of salicylamide and gentisamide. The time course for O2 consumption and glyoxylate production indicates that salicylurate amidation is a two-step reaction. Salicylurate is first converted to N-salicyl-alpha-hydroxyglycine, which is ultimately dealkylated to salicylamide and glyoxylate. The enzymatically generated salicylamide and N-salicyl-alpha-hydroxyglycine were characterized by mass spectrometry and two-dimensional 1H-13C heteronuclear multiple quantum coherence NMR.
双功能肽基甘氨酸α-酰胺化单加氧酶（PAM）催化铜、抗坏血酸盐和氧气依赖性的C末端甘氨酸延伸肽、N-酰基甘氨酸以及胆汁酸甘氨酸共轭物裂解为相应的酰胺和乙醛酸。阿司匹林的两种已知代谢产物，水杨尿酸和龙胆尿酸，也是PAM的底物，可导致水杨酰胺和龙胆酰胺的形成。氧气消耗和乙醛酸生成的时间进程表明，水杨尿酸酰胺化是一个两步反应。水杨尿酸首先转化为N-水杨基-α-羟基甘氨酸，最终脱烷基生成水杨酰胺和乙醛酸。通过质谱和二维1H-13C异核多量子相干核磁共振对酶促生成的水杨酰胺和N-水杨基-α-羟基甘氨酸进行了表征。
