New ideas about enzyme reactions.

Since a proper substrate of an enzyme fits its active site closely, adsorption in the active site can occur only if all water is excluded from between them. Any subsequent reaction therefore takes place in the absence of solvent, i.e. as it would in the gas phase. The specificity and high rates of enzyme reactions can be explained immediately in terms of this analogy. Past experimental studies of enzyme mechanisms, based on analogy with reactions in solution, need to be reevaluated. Interpretation of enzyme reactions requires information concerning gas phase chemistry, which is usually lacking. The role of theoretical calculations in this connection is pointed out.