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许多具有生物活性的肽类天然产物都拥有羧基末端酰胺化的结构。酰胺的形成一般由天门冬氨酸合成酶类蛋白所催化,其过程包括以谷氨酰胺为底物原位生成氨,后者由ATP活化的羧基基团产生酰胺并伴随谷氨酸、AMP和PPi的释放。此外,很多动物激素的末端酰胺形成则包含一个二价金属离子依赖的氧化过程,通过羧基端延伸的甘氨酸残基Cα-位上羟基的引入而去烷基化,生成酰胺并释放乙醛酸。与上述两种常见的方式明显不同,中科院上海有机化学研究所生命有机国家重点实验室的研究人员,在硫肽类抗生素的生物合成途径中发现了一种内源性、非氧化的新型酰胺化形成机制。
Many of the bioactive peptide natural products possess a carboxy-terminal amidated structure. The formation of amides is generally catalyzed by aspartate synthase-like proteins, which process involves the in situ generation of ammonia with glutamine as a substrate that produces amides from ATP-activated carboxyl groups and with glutamic acid, AMP and PPi release. In addition, the terminal amide formation of many animal hormones involves a bivalent metal ion-dependent oxidation process that is dealkylated by the introduction of a hydroxyl group at the Cα-position of the glycine residue extending at the carboxy terminus to generate an amide and release glyoxylate. Obviously different from the above two common methods, researchers from Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, State Key Laboratory of Organic and Inorganic, found a novel endogenous, non-oxidative amidation in the biosynthetic pathway of thiopeptide antibiotics Form a mechanism.