The effects of glycerol. polyethylene glycol. fructose, glucose, sorbitol. and saccharose on the conformation and catalytic activity of alpha-chymotrypsin were studied in 0.1 M sodium phosphate buffer and buffered aqueous 60% ethanol (pH 8.0). The enzyme activity was practically completely lost within 10 min in 60%, ethanol, but in the presence of stabilizers the activity was retained. With the exception of polyethylene glycol, the stabilizing effect decreased with increase of the incubation time. The preservation of the catalytic activity was accompanied by changes in the secondary and tertiary structures of a-chymotrypsin. (C) 2002 Elsevier Science (USA). All rights reserved.