A study of interaction between alpha-chymotrypsin and 18-crown-6 in organic solvents by Raman spectroscopy

Conformational changes of alpha -chymotrypsin caused by its interactions wi th organic solvents and 18-crown-6 were studied by Raman spectroscopy. The IR spectra of a-chymotrypsin lyophilized in the presence and absence of 18- crown-6, in the solid state, in acetonitrile and cyclohexane, and at variou s relative enzyme and crown molar concentrations were recorded. Tris(hydrox ymethyl)aminomethane and its complexes with 18-crown-6 were used as chemica l models to study interaction between the amino groups of the protein and t he crown. The conformation of enzyme molecules in water was found to be dra stically different from that in the "dry" sample and in organic solvents. T he influence of the crown and solvents on conformation-sensitive enzyme ban ds is discussed.