The Electric Dipole Moment of Rhodopsin Solubilized in Triton X-100
Overview
Authors
Affiliations
The electric dipole moment of solubilized rhodopsin was determined with dielectric dispersion measurements. Rhodopsin was extracted from disc membranes of cattle rod outer segments with the nonionic detergent Triton X-100. The dipole moment of rhodopsin at its isoionic point in the detergent micelle is 720 D (150 charge-A). This value is comparable to dipole moments of nonmembrane proteins, especially those which tend to aggregate or polymerize. Flash irradiation of the rhodopsin results in an increase in the dipole moment of about 25 D (5 charge-A). The light-induced increase in dipole moment appears to be composed of two parts--a faster component related to a change in the number of protons bound by rhodopsin and a slower component apparently independent of the change in proton binding.
Vohnsen B Biomed Opt Express. 2014; 5(5):1569-87.
PMID: 24877016 PMC: 4026908. DOI: 10.1364/BOE.5.001569.
Anisotropic electric properties of purple membrane and their change during the photoreaction cycle.
Kimura Y, Fujiwara M, Ikegami A Biophys J. 1984; 45(3):615-25.
PMID: 6713073 PMC: 1434873. DOI: 10.1016/S0006-3495(84)84200-9.
Kell D, Harris C Eur Biophys J. 1985; 12(4):181-97.
PMID: 4043002 DOI: 10.1007/BF00253845.
Distribution of charge on photoreceptor disc membranes and implications for charged lipid asymmetry.
Tsui F, Sundberg S, Hubbell W Biophys J. 1990; 57(1):85-97.
PMID: 2153422 PMC: 1280645. DOI: 10.1016/S0006-3495(90)82509-1.
Electric field effects in bacteriorhodopsin.
Shinar R, Druckmann S, OTTOLENGHI M, Korenstein R Biophys J. 1977; 19(1):1-5.
PMID: 880320 PMC: 1473260. DOI: 10.1016/S0006-3495(77)85558-6.