Kinetics of Na+, K+-ATPase inhibition by calcitonin and neurotensin.

M. G. LÓPEZ ORDIERES ; G. RODRÍGUEZ DE LORES ARNAIZ

Current Topics in peptide and protein Research

Research Trends

Año: 2014 vol. 15 p. 63 - 70

0972-4524

M. G. López Ordieres y G. Rodríguez de Lores Arnaiz (2014). Kinetics of Na+, K+-ATPase inhibition by calcitonin and neurotensin. Current Topics in Peptide & Protein Research 15, 63-70.The kinetics of interaction between the peptides calcitonin with neurotensin, and synaptosomal membrane Na/K-ATPase activity was characterized in this study. Calcitonin is a 32-amino acid peptide produced by the thyroid gland, whose main role is to prevent bone reabsorption. Calcitonin produced non-competitive inhibition versus potassium. At variance, this peptide produced uncompetitive and competitive inhibition versus sodium and ATP, respectively. Neurotensin is a basic tridecapeptide which also inhibits Na/K-ATPase activity. This peptide produced competitive interaction versus sodium but non-competitive inhibition versus potassium and ATP. In summary, both calcitonin and neurotensin behave as enzyme inhibitors, each one with characteristic type inhibitions versus substrates potassium, sodium or ATP. These differences are attributable to their proper structure and may account for their distinct functionality.