Isothermal microcalorimetric study of the pH dependence of the interactions between a cellulase and a beta-blocker

Gotmar, G
Özen, Can
Serpersu, E
Guiochon, G
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.


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A series of alkenes and alkynes was subjected to reduction with hydrazine hydrate in ethanol in the presence of oxygen. An efficient method was developed for the reduction of C-C double bonds and C-C triple bonds with diimide, generated in situ from hydrazine hydrate by oxidation with oxygen. The reduction process proceeded for 24-48 hours with high chemoselectivity and excellent yields. This reduction procedure offers synthetic advantages over metal-catalyzed hydrogenation as well as other systems.
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The low and high temperature bromination reactions of bromobenzonorbornadiene derivatives were studied and the possible role of a neighboring group in rearrangements was investigated. New polybrominated benzonorbornadiene and benzonorbornene derivatives were synthesized. All compounds were characterized property Using NMR spectroscopy.
Citation Formats
G. Gotmar, C. Özen, E. Serpersu, and G. Guiochon, “Isothermal microcalorimetric study of the pH dependence of the interactions between a cellulase and a beta-blocker,” JOURNAL OF CHROMATOGRAPHY A, pp. 49–53, 2004, Accessed: 00, 2020. [Online]. Available: