Energy transfer by chlorophyll beta in detergent micelles.
The concentration-dependent depolarization, concentration-dependent quenching, absorption and fluorescence spectra in solutions of chlorophyll beta-containing detergent micelles with Triton X-100 were studied in a concentration range of c equal to 0.4 muM-0.6mM chlorophyll beta and cd equal to 0.4-7.0 mM Triton X-100. The concentration-dependent depolarization obeys Förster's theory of depolarization of fluorescence with a transfer distance parameter R0 equal to 43 plus or minus 2 A. The concentration-dependent quenching  is described by an empirical formula for the relative fluorescence yield n/n0 equal to 1/[1+(c/c1/2)-2] given by Kelly and Porter (Kelly A. R. and Porter, G. (1970) Proc. R. Soc. Lond. Ser. A. 315, 149-161). With increasing chlorophyll beta concentration the red absorption band at 650 nm is shifted toward a longer wavelength and its width increases by 10nm, the intensity of the long wave fluorescence band increases about 720 nm. The results analysed in terms of these findings lead to the conclusions that chlorophyll beta molecules are (a) locally concentrated in the micelles up to the concentration range of in vivo conditions, (b) partly in an aggregated state capable for fluorescence, (c) the chlorophyll beta yields chlorophyll beta homotransfer may be about 3-26% of the homotransfer chlorophyll alpha yields chlorophyll-alpha depending on the ratio of their concentrations.
D002734:Chlorophyll / Q000302:isolation & purification; D002845:Chromatography; D003102:Colloids; D004735:Energy Transfer; D007700:Kinetics; D008433:Mathematics; D008823:Micelles; D010944:Plants; D011092:Polyethylene Glycols; D000644:Quaternary Ammonium Compounds; D013050:Spectrometry, Fluorescence
D003102:Colloids; D008823:Micelles; D000644:Quaternary Ammonium Compounds; D002734:Chlorophyll; D011092:Polyethylene Glycols