Open AccessFluidity in Hydrophobic Protein Regions of Synaptic Membranes
Author(s) -
HOSS Wayne,
ABOOD Leo G.
Publication year - 1974
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1974.tb03885.x
Subject(s) - membrane , quenching (fluorescence) , membrane fluidity , tryptophan , chemistry , viscosity , reaction rate constant , diffusion , fluorescence , bilayer , lipid bilayer , biophysics , kinetics , biochemistry , materials science , thermodynamics , biology , physics , amino acid , quantum mechanics , composite material
Dynamic quenching of native tryptophan fluorescence has been used to assess the fluidity of intact membrane suspensions. The photophysical quenching of tryptophan fluorescence by chloroform occurred by a diffusion‐controlled process where one‐half of all collisions were effective. The bimolecular rate constant for quenching was directly proportional to the fluidity for a series of solvents. Estimation of the rate constant in the membranes from quenching data indicated that the viscosity of membrane proteins (about 1 cP) was at least an order‐of‐magnitude lower than the values reported for lipid bilayer regions of nerve membranes.