Abstract
Water-soluble polyelectrolytes in interaction with proteins are described. These polyelectrolytes make it possible to investigate enzyme-catalyzed reactions in cooled mixed solvents without the usual effects of their organic solvent component on enzyme specific activity. The applicability of techniques developed is illustrated by results obtained with trypsin. The possibility of an electrostatic "sorting out" of solvents and its potentialities in cryoenzymology are discussed.