“…A possibility for gaining further insight into this question arises from the fact that the magnitudes of Hammett p values for acyl transfer reactions of acyl-substituted benzoate esters have been found to be highly sensitive to the charge on the attacking nucleophile (Caplow & Jencks, 1962; Williams & Salvador!, 1971; Hubbard & Kirsch, 1972). Indeed, the p values for the rates of deacylation of substituted benzoyl chymotrypsins are very close to those observed for alkaline hydrolysis (Caplow & Jencks, 1962;Williams & Salvador!, 1971; Wang & Shaw, 1972; Amshey et al, 1975;Kirsch et al, 1968; Kirsch, 1972). These observations support the conclusion that the net charge of the charge relay system is -1 in deacylation.…”