The effect of vesicular L-$alpha$-phosphatidylcholine on the rate of formation of all-trans-N-retinylidene-n-butylamine (3) and on the regeneration kinetics of bacteriorhodopsin pigment from retinal and bacterio-opsin have been studied. An estimate of the relative positions of retinal and n-butylamine in the vesicles has been made by fluoresence quenching experiments. Partition coefficient of retinal and microviscosity of the retinal-binding region have also been determined. The results are discussed in terms of the nature of chemical interaction between retinal and amine in a lipid environment.