ENZYMATIC INACTIVATION OF PEPTIDE HORMONES POSSESSING A C-TERMINAL AMIDE GROUP*

AUTOR(ES)

Glass, John D.

RESUMO

A partially purified enzyme extracted from the bladder of the toad, Bufo marinus L., was found to cleave the glycine amide moiety from oxytocin, 8-lysine-vasopressin, 8-arginine-vasopressin, and other hormone analogs terminating in a primary carboxamide group; however, this enzyme does not attack hormone analogs terminating with a methylamide, dimethylamide, or carboxyl group. Preliminary experiments indicate that a functionally similar enzyme is also present in the mammalian kidney, the major target organ of neurohypophyseal antidiuretic hormones. This enzyme, besides inactivating oxytocin and 8-lysine-vasopressin, also cleaves the phenylalanine amide moiety from a tetrapeptide analog of gastrin, another hormone terminating in a primary carboxamide group. Attention is drawn to the possible general significance of “carboxamidopeptidases” for the termination of the action of peptide hormones in which the C-terminal amino acid residue bears a carboxamide group.

Documentos Relacionados

• C-terminal truncation of the retinoblastoma gene product leads to functional inactivation.
• The C-terminal region of human angiogenin has a dual role in enzymatic activity.
• Mutations in the C-terminal fragment of DnaK affecting peptide binding.
• Structure of the C-terminal end of the nascent peptide influences translation termination.
• Role of the C-terminal domain in inactivation of brain and cardiac sodium channels