The study of photoconduction of artificial lipid membranes incorporating rhodopsin. The simultaneous changes of membrane conduction and rhodopsin fluorescence

The protein fluorescence changes of rod outer segment fragments during bleaching were studied. Flash caused a fluorescence intensity drop by about 6%. The time constant of this process was30 msec and coincided with the time constant of increasing the permeability of an artificial lipid membrane containing rhodopsin and of Metarhodopsin I decay. In the presence of hydroxylamine the fluorescence intensity increases after the initial drop. The second process time constant was about 300 msec and coincided with the conduction drop time constant of the artificial membrane containing rhodopsin. A new intermediate — Metarhodopsin II₁ is proposed. It has the Metarhodopsin II absorption spectrum, lives for about 300 msec at room temperature, does not react with hydroxylamine, and increases the permeability of a disk membrane.