The effect of alcohols on aequorin luminescence

The effect of alcohols from ethanol to octanol on aequorin luminescence was biphasic; enhancement of both peak light and total photon yield at low concentrations, and inhibition of these parameters at high concentrations. The potency of alcohols to exert these effects was in the same order as the oil/water partition coefficients of the alcohols. It is argued that neither of these effects is related to calcium binding by aequorin, since alcohols enhanced calcium-independent luminescence, and the inhibition of responses is not associated with a reduction in the rate of aequorin 'consumption' on binding of calcium.