以促肾上腺皮质激素（ACTH）-（1-16）-NH2为模型底物，研究脑突触膜中肽酶对促肾上腺皮质激素NH2末端的作用。

Action of peptidases in brain synaptic membranes on the NH2-terminus of adrenocorticotropin using ACTH-(1-16)-NH2 as a model substrate.

作者信息

Wang X C, Burbach J P, Verhoef J C

出版信息

Biochem Biophys Res Commun. 1983 Feb 28;111(1):259-65. doi: 10.1016/s0006-291x(83)80145-4.

Abstract

The action of brain peptidases on NH2-terminal sequences of adrenocorticotropin was studied by incubation of ACTH-(1-16)-NH2 under different pH conditions. Profiles of metabolites and time course of product formation were obtained by HPLC analysis of the digests. Fragments of ACTH-(1-16)-NH2 were isolated and characterized by their amino acid composition and NH2-terminal groups. Both at pH 7.4 and pH 8.5 the following fragments were found: ACTH-(3-16)-NH2, ACTH-(4-16)-NH2, ACTH-(5-16)-NH2, and ACTH-(7-16)-NH2. At pH 7.4 the major products were ACTH-(4-16)-NH2 and ACTH-(7-16)-NH2, while the peptide ACTH-(3-16)-NH2 was the main metabolite at pH 8.5. The nature of identified peptides and the time course of their formation demonstrates that aminopeptidase activities predominate in the conversion of the NH2-terminus of adreno-corticotropin and related peptides by brain synaptic membranes.

摘要

通过在不同pH条件下孵育促肾上腺皮质激素（ACTH）-(1-16)-NH₂，研究了脑肽酶对促肾上腺皮质激素NH₂末端序列的作用。通过对消化产物进行高效液相色谱分析，获得了代谢产物图谱和产物形成的时间进程。分离出促肾上腺皮质激素-(1-16)-NH₂的片段，并通过其氨基酸组成和NH₂末端基团进行表征。在pH 7.4和pH 8.5时均发现了以下片段：促肾上腺皮质激素-(3-16)-NH₂、促肾上腺皮质激素-(4-16)-NH₂、促肾上腺皮质激素-(5-16)-NH₂和促肾上腺皮质激素-(7-16)-NH₂。在pH 7.4时，主要产物是促肾上腺皮质激素-(4-16)-NH₂和促肾上腺皮质激素-(7-16)-NH₂，而在pH 8.5时，肽促肾上腺皮质激素-(3-16)-NH₂是主要代谢产物。已鉴定肽段的性质及其形成的时间进程表明，氨肽酶活性在脑突触膜对促肾上腺皮质激素及相关肽NH₂末端的转化中占主导地位。