Counterions and the bacteriorhodopsin proton pump
نویسندگان
چکیده
منابع مشابه
Carboxyl groups and the proton pump of bacteriorhodopsin.
The purple membrane isolated from Halobacterium halobium contains only a single protein, bacteriorhodopsin, which functions as a light-driven proton pump. Substantial structural information has been obtained which has led to specific models of protein structure in the membrane (Engelman et al., 1982; Huang et al., 1982; Agard & Stroud, 1982). The retinal chromophore of bacteriorhodopsin is boun...
متن کاملMolecular dynamics study of the proton pump cycle of bacteriorhodopsin.
Retinal isomerization reactions, which are functionally important in the proton pump cycle of bacteriorhodopsin, were studied by molecular dynamics simulations performed on the complete protein. Retinal isomerizations were simulated in situ to account for the effects of the retinal-protein interactions. The protein structure employed was that described in Nonella et al. [Nonella, M., Windemuth,...
متن کاملLeptosphaeria rhodopsin: bacteriorhodopsin-like proton pump from a eukaryote.
Bacteriorhodopsin-like proteins provide archaea and eubacteria with a unique bioenergetic pathway comprising light-driven transmembrane proton translocation by a single retinal-binding protein. Recently, homologous proteins were found to perform photosensory functions in lower eukaryotes, but no active ion transport by eukaryotic rhodopsins was detected. By demonstrating light-driven proton pum...
متن کاملEffect of genetic modification of tyrosine-185 on the proton pump and the blue-to-purple transition in bacteriorhodopsin.
The retinylidene chromophore mutant (Y185F) of bacteriorhodopsin, in which Tyr-185 is substituted by phenylalanine, is examined and compared with wild-type bacteriorhodopsin expressed in Escherichia coli; both were reinstituted similarly in vesicles. The Y185F mutant shows (at least) two distinct spectra at neutral pH. Upon light absorption, the blue species (which absorbs in the red) behaves a...
متن کاملA correlation between proton pumping and the bacteriorhodopsin photocycle.
In an attempt to establish a relationship between proton pumping and the photocycle intermediates of bacteriorhodopsin, we have studied the effects of pH and temperature on flash-induced proton pumping and the photointermediates O640 and M412. The relative quantum yield of flash-induced proton pumping is both pH and temperature dependent. It is high in the acid pH range and at low temperatures ...
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ژورنال
عنوان ژورنال: FEBS Letters
سال: 1988
ISSN: 0014-5793
DOI: 10.1016/0014-5793(88)81147-5