ETHANOL BINDING TO A MODEL CARBOHYDRATE, GLYCOGEN

The binding affinity of ethanol for carbohydrates is unknown. Glycocon jugates are postulated to be sensitive targets of ethanol action. The glycogen content of muscle, liver, and brain is sensitive to ethanol. To explore whether carbohydrates as a class have a specific affinity t o bind ethanol, we measured the binding of ethanol and other small mol ecules to the carbohydrate glycogen. Ethanol binding was found to be w eak. The polar alcohol, glycerol, bound to glycogen with a greater aff inity than ethanol did. Other small polar molecules (methanol, sucrose , acetate, glycine, and dimethyl sulfoxide) also bound more strongly t han ethanol did. Ethanol and glycerol binding were concentration indep endent. No evidence of saturable or specific sites for these alcohols was obtained. Water binding was determined and was in agreement with h ydrodynamic measures. Water binding exceeded the binding of all solute s studied. The loosely structured water of hydration in glycogen appar ently was able to accommodate polar solutes, but tended to exclude eth anol and, to a lesser extent, methanol. We conclude that carbohydrates as a class exhibit no strong affinity or specificity for ethanol. Cop yright (C) 1996 Elsevier Science Inc.