Energy transfer by chlorophyll a in detergent micelles

The process of energy transfer was studied in the chlorophyll a-containing detergent micelle, serving as a possible model of the photosynthetic unit. Chlorophyll a was added to aqueous solutions of the detergent Triton X-100 and incorporated into the micelles. The energy transfer process was studied by investigating the concentration depolarization of fluorescence of chlorophyll a. On the basis of the experimental depolarization curves as well as the value of the Förster parameter $\text{R}{}_0\text{= 56}\text{A}\text{?}$ calculated from the overlap of absorption and fluorescence spectra it was concluded that energy transfer between chlorophyll a molecules in this model follows the Förstertype mechanism of inductive resonance. Furthermore it was found that the local concentration of chlorophyll a in the micelles is higher by 1–3 orders of magnitude than its overall concentration in the solution and by choosing the appropriate ratio between the concentration of chlorophyll a and the detergent it is possible to reach the in vivo chlorophyll concentration of 0.1 M within the micelles. Thus the chlorophyll-detergent micelle model may be applied as a model of the separate package-type photosynthetic unit.