Intrinsic Molecules in Fluid Phospholipid Bilayers. Fluorescence Probe Studies

• DOI: 10.1111/j.1432-1033.1981.tb05184.x
• Publication Date: 2005-03-03T21:06:56Z
• Authors: Winfried HOFFMANN; David A. PINK; Colin RESTALL; Dennis CHAPMAN
• Keywords: Electron Transport Complex IV; 0301 basic medicine; 03 medical and health sciences; Cholesterol; Spectrometry, Fluorescence; Membrane Fluidity; Lipid Bilayers; Gramicidin; Molecular Conformation; Diphenylhexatriene; Models, Biological; Mathematics

Fluorescence probe data using 1,6-diphenyl-1,3,5-hexatriene for various concentrations of intrinsic molecules (cholesterol, gramicidin A and cytochrome oxidase) within fluid lipid bilayers have been examined. The polarization value increases with increasing concentration molecule then approaches a limiting value. Empirical curve-fitting the experimental data, change concentration, shows that each system can be fitted approximately by an exponential curve. theory has constructed based upon assumption only one need adjacent to fluorescent affect its motion drastically. in depends probability p all positions next chain being free molecules. calculated it is shown p= (1 - x)m where x=c or depending on whether spans bilayer not. approximation = e−Mx gives good fit x, thereby explaining observed phenomenological fit. interpreted show protein-protein contacts increase as protein bilayer. An apparent dichotomy between results from fluorescence deuterium magnetic resonance explained terms dominant hindrance interaction (protein) whilst individual C2H2 groups may exhibit greater disorder.