An aminopeptidase activity in bovine pituitary secretory vesicles that cleaves the N‐terminal arginine from β‐lipotropin60–65

FEBS Letters

Russell, James T.¹  Loh, Y.Peng¹  Gainer, Harold¹ 

[1] Laboratory of Neurochemistry and Neuroimmunology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20205, USA

关键词: AminopeptidaseProhormone processing (converting) enzyme;    Secretory vesicle;    Neurohypophysis;    Intermediate lobe;   

DOI  :  10.1016/0014-5793(84)80586-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Secretory vesicles isolated from the neural and intermediate lobes of the bovine pituitary contained a membrane-bound aminopeptidase activity which cleaved arginine from β-LPH_60–65 (Arg-Tyr-Gly-Gly-Phe-Met) and Arg-MCA. Neither methionine enkephalin (Tyr-Gly-Gly-Phe-Met) nor Substance P, which has an N-terminal arginine followed by a proline, could serve as substrates for this aminopeptidase activity; nor could cathepsin B-like or chymotrypsin-like enzyme activities be detected in the vesicle preparations. Maximal enzyme activity was at pH 6.0, and the activity was inhibited by EDTA, stimulated by Co²⁺and Zn²⁺, but was unaffected by leupeptin, pepstatin A, phenylmethylsulfonyl fluoride and p-chloromercuribenzenesulfonate, suggesting that the enzyme is a metalloaminopeptidase. The presence of this aminopeptidase activity in secretory vesicles suggests that it may be involved in peptide prohormone processing.

【 授权许可】

Unknown