Analysis of the binding of Ca2+ to gramicidin A in ethanol in terms of the dimer-monomer conformational equilibrium.
This study reports the first direct observation of the binding of Ca2+ to gramicidin A in ethanol, analysed in terms of the polypeptide dimer-monomer conformational equilibrium. High performance size-exclusion chromatography has been successfully used to elucidate the binding mechanism and to determine the rate constants as well as the stoichiometry of the processes involved. In addition, fluorescence intensity and anisotropy measurements have revealed a dependence of the number of accessible Ca2+-binding sites on the peptide concentration.
Braco
L
L
Department de Bioquímica i Biología Molecular, Facultades de Ciencias, Universitat de Valencia, Spain.
Bañó
C
C
Campos
A
A
Abad
C
C
D002118:Calcium; D002850:Chromatography, Gel; D000431:Ethanol; D006096:Gramicidin; D007700:Kinetics; D011485:Protein Binding; D011487:Protein Conformation
D006096:Gramicidin; D000431:Ethanol; D002118:Calcium