title: Monitoring membrane protein rotational diffusion using time-averaged phosphorescence.
abstract: Rotational motions of membrane proteins have previously been measured using time-dependent phosphorescence techniques. This paper discusses a method of examining membrane protein mobility at temperatures relevant to biological systems, using a technique similar to steady-state fluorescence. The method is demonstrated using sarcoplasmic reticulum ATPase labelled with erythrosin isothiocyanate, both in its natural condition and crosslinked by incubation with glutaraldehyde. The experimentally-observed dependence of phosphorescence anisotropy on temperature is compared to a calculated anisotropy-temperature curve. Comparison is made between the anisotropy decay curves obtained by time-averaged phosphorescence and steady-state fluorescence.
mesh_terms: D000818:Animals; D004058:Diffusion; D007700:Kinetics; D008163:Luminescent Measurements; D008565:Membrane Proteins / Q000302:isolation & purification*; D008856:Microscopy, Fluorescence; D009132:Muscles / Q000032:analysis; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000032:analysis*; D013997:Time Factors
chemical_list: D008565:Membrane Proteins