Proline Rich Peptides of Neurohypophysial Origin: Related Peptides and Possible Functions

Proline rich polypeptide 1 (PRP-1) was isolated from the neurosecretory granules of bovine neurohypophysis and thoroughly characterized by Professor A. Galoyan and coauthors. BLAST analyses of PRP-1 with proteins of protein data bank indicated, that it is the C-terminus of third constituent of pre-pro-arginine vasopressin – copeptin, for all studied mammal species, as showed Galoyan and coauthors for bovine case. Also, BLAST analyses indicated, that the amino acid motive of PRP-1 is conservative in the course of the evolution, and occurred among enzymes of prokaryotic and eukaryotic origin Obtained to date data indicate multiple functionalities of this polypeptide, through to its diverse modulatory actions on set of different receptors. Using the AutoDock vina software it was shown, that PRP-1 and its homologues strongly interact with receptors, such as: mouse phosphorylated mitogen activated protein kinase 14, mouse toll like receptor 4, human Ca-sensing receptor, human epithelial growth factor receptor and human superoxide dismutase 1. As these receptors play important role in multiple cell signaling processes, the importance of their ligand peptides and homologues is obvious. But it should be stated, that, through docking experiments although are very informative, they should be considered as supplementary to real physical experiments, which should be carried out with the same receptors.