Oldham C D, Li C, Girard P R, Nerem R M, May S W
School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta 30332.
Biochem Biophys Res Commun. 1992 Apr 15;184(1):323-9. doi: 10.1016/0006-291x(92)91196-w.
Carboxy-terminal amidation is a prevalent post-translational modification necessary for the bioactivity of many peptides. We now report that the two enzymes essential for amidation, peptidylglycine alpha-monooxygenase (PAM) and peptidylamidoglycolate lyase (PGL), are present in both the cytosol and membrane fractions of cultured bovine aortic endothelial cells. Endothelial PAM exhibits ascorbate-dependent turnover and is inactivated by the mechanism-based inactivator, 4-phenyl-3-butenoic acid (PBA), whereas PGL activity is independent of ascorbate and is not affected by PBA. These enzymological characteristics correspond to those of amidating enzymes from other tissues. These results suggest a heretofore unrecognized role for alpha-amidated peptides in cardiovascular function.
羧基末端酰胺化是许多肽生物活性所必需的普遍的翻译后修饰。我们现在报告，酰胺化所必需的两种酶，肽基甘氨酸α-单加氧酶（PAM）和肽基酰胺基乙醇酸裂解酶（PGL），存在于培养的牛主动脉内皮细胞的胞质溶胶和膜部分中。内皮细胞PAM表现出抗坏血酸依赖性周转，并被基于机制的灭活剂4-苯基-3-丁烯酸（PBA）灭活，而PGL活性不依赖于抗坏血酸，且不受PBA影响。这些酶学特征与来自其他组织的酰胺化酶的特征一致。这些结果表明α-酰胺化肽在心血管功能中具有迄今未被认识的作用。
