Nonenzymatic peptide alpha-amidation. Implications for a novel enzyme mechanism.

Exocrine secretion granules contain peptide amidation activity.

Exocrine secretion granules from the rat parotid gland contain a carboxyl-terminal peptide alpha-amidation enzyme resembling closely an enzyme from the pituitary (peptidyl-glycine alpha-amidating monooxygenase) that functions in post-translational processing of secretory polypeptides within neural and endocrine secretion granules. alpha-Amidation is a characteristic (often essential) chemical f...

Characterization of a Peptide & - Amidation Activity from Rat Anterior Pituitary

A secretory granule associated enzymatic activity from the rat anterior pituitary that can convert the synthetic peptide D-Tyr-Val-Gly into D-Tyr-Val-NH2 is described. Due to the presence of inhibitory activity in the cytosol and rough endoplasmic reticulum/Golgi apparatus fractions, the a-amidation activity is barely detectable in crude rat anterior pituitary homogenates. The a-amidation activ...

Identification of a Novel Tumor-Binding Peptide for Lung Cancer Through in-vitro Panning

Tumor-targeted therapies are playing growing roles in cancer research. The exploitation of these powerful therapeutic modalities largely depends on the discovery of tumor-targeting ligands. Phage display has proven a promising high throughput screening tool for the identification of novel specific peptides with high binding affinity to cancer cells. In the present study, we describe the use of ...

Nonenzymatic, self-elimination degradation mechanism of glutathione.

In the present in vitro studies, evidence is provided showing that glutathione (GSH) can undergo spontaneous, nonenzymatic auto-degradation. The initial cleavage of the Glu-Cys bond involves nucleophilic attack of the N-terminal amino group of GSH at the gamma-carbonyl side chain, followed by an unusual cleavage of the Cys-Gly amide bond that is complete within 3-5 weeks in the physiological pH...

Glucagon-like peptide-1 receptor-atrial natriuretic peptide axis: a novel mechanism for blood pressure regulation.