The Snake Venom Peptide Bj-PRO-7a Is a M1 Muscarinic Acetylcholine Receptor Agonist

Author(s)

Negraes, Priscilla D. ^{[1, 2]} ; Lameu, Claudiana ^{[1, 2]} ; Hayashi, Mirian A. F. ^[3] ; Melo, Robson L. ^[2] ; Camargo, Antonio C. M. ^{[2, 4]} ; Ulrich, Henning ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Quim, Dept Bioquim, BR-01498 Sao Paulo - Brazil

^[2] Inst Butantan, Ctr Appl Toxinol CAT CEPID, Sao Paulo - Brazil

^[3] Univ Fed Sao Paulo, Dept Farmacol, Sao Paulo - Brazil

^[4] Univ Sao Paulo, Inst Ciencias Biomed, Dept Biol Celular & Dev, BR-05508 Sao Paulo - Brazil

• Document type: Journal article
• Source: Cytometry Part A; v. 79A, n. 1, p. 77-83, JAN 2011.
• Web of Science Citations: 9

Abstract

Proline-rich peptides from Bothrops jararaca venom (Bj-PRO) were characterized based on the capability to inhibit the somatic angiotensin-converting enzyme. The pharmacological action of these peptides resulted in the development of Captopril, one of the best examples of a target-driven drug discovery for treatment of hypertension. However, biochemical and biological properties of Bj-PROs were not completely elucidated yet, and many recent studies have suggested that their activity relies on angiotensin-converting enzyme-independent mechanisms. Here, we show that Bj-PRO-7a (<EDGPIPP) specifically activates {[}Ca(2+)](i) transients in CHO-M1 cells expressing heterologous rat M1 muscarinic subtype. The activation curve established by microfluorimetry in CHO-M1 cells using increasing concentrations of Bj-PRO-7a reached the maximum response in the presence of 3 mu M Bj-PRO-7a (EC(50) = 0.25 +/- 0.07 mu M). The variation observed by calcium imaging in these cells ranged from 52 to 1218 nM (EC(50) = 0.31 +/- 0.12 mu M). {[}Ca(2+)](i) responses in CHO-M1 cells were largely inhibited by pirenzepine, a specific M1 antagonist. Neural-differentiated P19 cells expressing endogenous M1 receptors were also responsive to Bj-PRO-7a application, whereas no such response was observed in undifferentiated P19 cells not expressing muscarinic receptors. As further support for its specific action on M1 receptors, the peptide did not activate M3 subtypes in transfected CHO cells. Our findings provide a novel M1 muscarinic receptor agonist that could be used for basic research and even for pharmacological applications. (C) 2010 International Society for Advancement of Cytometry (AU)

• FAPESP's process: 06/61285-9 - Molecular basis of differentiation of stem and neural progenitor cells
• Grantee: Alexander Henning Ulrich
• Support Opportunities: Research Projects - Thematic Grants