Artículos de revistas
Reduced pH induces an inactive non-native conformation of the monomeric bothropstoxin-I (Lys49-PLA(2))
Fecha
2009Registro en:
TOXICON, v.54, n.3, p.373-378, 2009
0041-0101
10.1016/j.toxicon.2009.04.022
Autor
OLIVEIRA, Arthur H. C. de
FERREIRA, Tatiana L.
WARD, Richard J.
Institución
Resumen
Bothropstoxin-I (BthTx-I), a Lys49-PLA(2) from Bothrops jararacussu venom, permeabilizes membranes by a non-hydrolytic Ca(2+)-independent mechanism. The BthTx-I showed activity against liposomes including 10% and 50% negatively charged lipids at pH 7.0, but not at pH 5.0. Nevertheless, ultracentrifugation and FRET demonstrated that at pH 5.0 the BthTx-I is bound to 50% negatively charged membranes. ANS binding identified a non-native monomeric conformation at pH 5.0, suggesting that tertiary structure alterations result in activity loss of the BthTx-I at low pH. (C) 2009 Elsevier Ltd. All rights reserved.