Studies on the Mechanism of the Enzymatic Photoisomerization of Retinal

The honeybee retina contains the enzyme photoisomerase that converts all-trans-retinal to 11-cis-retinal in light within the visible range. The activity of the bee photoisomerase was studied on all-trans-retinal under pulses of laser light. The experimental data were fitted with a simple equation that describes the mechanism of the isomerization reaction based on three steps having different time constants.