Titration of Asp-85, the proton acceptor and part of the counterion in bacteriorhodopsin, over
a wide pH range (2–11) leads us to the following conclusions: 1) Asp-85 has a complex …

Bacteriorhodopsin is a seven-transmembrane helical protein that contains all-trans retinal. In
this light-driven pump, a reaction cycle initiated by photoisomerization to 13-cis causes …

Retinal proteins are membrane-bound protein pigments that contain vitamin A aldehyde
(retinal) as the chromophore. They include the visual pigment rhodopsin and four additional …

We have found that extensively washed purple membrane has about 1 calcium and 3-4
magnesium ions bound per bacteriorhodopsin molecule. When these divalent cations are …

An investigation of the dark equilibria between different chromophores of bacteriorhodopsin
(BR) and studies of the kinetics of their interconversion and photochemical activity have led …

The factors determining the pH dependence of the formation and decay of the O
photointermediate of the bacteriorhodopsin (bR) photocycle were investigated in the wild …

Purple membrane suspensions change their color to blue and the absorption maximum
shifts to 608 nm when the membrane is deionized on a cation exchange column or when it is …

Thermal unfolding experiments on bacteriorhodopsin in mixed Phospholipid/detergent
micelles were performed. Bacteriorhodopsin was extracted from the purple membrane in a …

Purple membrane (lambda max= 568 nm) can be converted to blue membrane (lambda
max= 605 nm) by either acid titration or deionization. Partially delipidated purple membrane …

We have developed a surface model of purple membrane and applied it in an analysis of the
purple-to-blue color change of bacteriorhodopsin which is induced by acidification or …