Isothermal microcalorimetric study of the pH dependence of the interactions between a cellulase and a beta-blocker.
The influence of the pH on the complexation equilibria between (S)- or (R)-alprenolol and the cellulase Cel7A was investigated by isothermal titration calorimetry. The results obtained agree with those of previous, similar studies of the same equilibria in which the protein was immobilized on silica particles, packed in a chromatographic column. The association constant and the complexation enthalpy and entropy of the (S)-enantiomer increase with increasing pH. For (R)-alprenolol, the binding is endothermic at all pH values. Thus, for both enantiomers in the pH range 5.5-6.8, the binding is an entropically driven process.
Götmar
Gustaf
G
Department of Chemistry, The University of Tennessee, Knoxville, TN 37996-1600, USA.
Ozen
Can
C
Serpersu
Engin
E
Guiochon
Georges
G
D000319:Adrenergic beta-Antagonists / Q000737:chemistry*; D000526:Alprenolol / Q000737:chemistry*; D002151:Calorimetry / Q000379:methods*; D002480:Cellulase / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D013237:Stereoisomerism
D000319:Adrenergic beta-Antagonists; D000526:Alprenolol; D002480:Cellulase