Carbocyanine dye orientation in red cell membrane studied by microscopic fluorescence polarization.
The orientation of an amphipathic, long acyl chain fluorescent carbocyanine dye [diI-C18-(3)] in a biological membrane is examined by steady-state fluorescence polarization microscopy on portions of single erythrocyte ghosts. The thermodynamically plausible orientation model most consistent with the experimental data is one in which the diI-C18-(3) conjugated bridge chromophore is parallel to the surface of the cell and the acyl chains are imbedded in the bilayer parallel to the phospholipid acyl chains. Comparison of the predictions of this model with the experimental data yields information on the intramolecular orientations of the dye's transition dipoles and on the dye's rate of rotation in the membrane around an axis normal to the membrane. To interpret the experimental data, formulae are derived to account for the effect of high aperture observation on fluorescence polarization ratios. These formulae are generally applicable to any high aperture polarization studied on microscopic samples, such as portions of single cells.
D002232:Carbocyanines; D004910:Erythrocyte Membrane / Q000648:ultrastructure*; D004912:Erythrocytes / Q000648:ultrastructure*; D005456:Fluorescent Dyes; D006801:Humans; D008433:Mathematics; D008856:Microscopy, Fluorescence / Q000379:methods; D011804:Quinolines
D002232:Carbocyanines; D005456:Fluorescent Dyes; D011804:Quinolines; C024286:3,3'-dioctadecylindocarbocyanine
Annu Rev Biophys Bioeng. 1978;7:435-68
352245
Nature. 1978 Mar 30;272(5652):448-50
345127
Biochemistry. 1978 Aug 22;17(17):3604-9
567490
Science. 1977 Jan 21;195(4275):307-9
556653
Proc Natl Acad Sci U S A. 1971 Jun;68(6):1217-21
5288369
Biochim Biophys Acta. 1974 Nov 15;367(3):282-94
4429678
Biochemistry. 1974 Jul 30;13(16):3315-30
4842277
Biochemistry. 1973 Jan 16;12(2):268-75
4683001
J Membr Biol. 1977 May 6;33(1-2):109-40
864684