Structural and Functional Characterization of a Mutant of Pseudocerastes persicus Natriuretic Peptide
Abstract:We hereby report on a mutational analysis of a novel natriuretic peptide (PNP), recently isolated by us from the Iranian snake venom. The PNP variant (mutPNP) with four substitutions (G16T, K18S, R21S, G23R) and a disulfide bonded ring shortened by 3 residues. mutPNP peptide was expressed in pET32 and purified by affinity separation on nickel resin followed by RP-HPLC chromatography. The conformation of mutPNP was characterized in solution by 1H nuclear magnetic resonance spectroscopy, where it was found that the 14-residue disulfide bonded ring, like the 17- residue ring in PNP, retains a high degree of conformational flexibility. The conformation of mutPNP bound to NPR-C receptor was predicted by homology protein structure modeling. When injected intravenously into rats, mutPNP, in contrast to PNP had no physiological effect on blood pressure or on diuresis. The loss of physiological activity is explained in terms of the modeled bound conformation and the ensemble of solution conformations obtained using the NMR constraints.
Document Type: Research Article
Affiliations: Institute of Biochemistry and Biophysics, Tehran University, P.O. Box 13145-1384, Tehran, Iran.
Publication date: March 1, 2006
More about this publication?
- Protein & Peptide Letters publishes short papers in all important aspects of protein and peptide research, including structural studies, recombinant expression, function, synthesis, enzymology, immunology, molecular modeling, drug design etc. Manuscripts must have a significant element of novelty, timeliness and urgency that merit rapid publication. Reports of crystallisation, and preliminary structure determinations of biologically important proteins are acceptable. Purely theoretical papers are also acceptable provided they provide new insight into the principles of protein/peptide structure and function.