Dynamic processes of visual transduction

@article{Applebury1984DynamicPO,
  title={Dynamic processes of visual transduction},
  author={Meredithe L. Applebury},
  journal={Vision Research},
  year={1984},
  volume={24},
  pages={1445-1454}
}
  • M. Applebury
  • Published 31 December 1984
  • Biology
  • Vision Research
Functional equivalence of metarhodopsin II and the Gt-activating form of photolyzed bovine rhodopsin.
TLDR
The similarity of these decay times provides direct evidence that meta II and rho* are present over the same time regime, and further supports the equivalence of these two forms of photoactivated rhodopsin.
Room temperature trapping of rhodopsin photointermediates.
TLDR
The present results suggest that large structural changes have occurred in the transition to this state of metarhodopsin II, and the utility of room temperature trapping of photostates in trehalose-water glasses is demonstrated.
Interconversion of metarhodopsins I and II: a branched photointermediate decay model.
TLDR
Analysis of deconvoluted equilibrium spectra acquired from samples identical with those used in the kinetics experiments confirmed the metarhodopin I-metarhodopsin II equilibrium constants, Keq, derived from the dynamic analyses.
LIGHT INDUCED INTERACTION BETWEEN RHODOPSIN AND GTP DEPENDENT PROCESSES IN ROD OUTER SEGMENTS—I. KINETIC ANALYSES OF LIGHT SCATTERING TRANSIENTS
TLDR
It has been observed that with decreasing GTP concentration, the rates of both processes decrease indicating that the two processes though first order are most likely bimolecular, first order in both GTP and the photolytic rhodopin intermediate (metarhodopsin II).
PHOTOLYSIS OF RHODOPSIN RESULTS IN DEPROTONATION OF ITS RETINAL SCHIFF'S BASE PRIOR TO FORMATION OF METARHODOPSIN II
TLDR
Results are not consistent with the simple scheme, but indicate that an intermediate with a deprotonated Schiff's base is formed nearly simultaneously with Metarhodopsin I upon the decay of Lumirhodopin.
Spectral and Kinetic Characterization of Visual Pigment Photointermediates
The literature describing intermediates formed after photolysis of visual pigments is reviewed. Results obtained near physiological temperatures using time-resolved optical density measurements in
Modulation of metarhodopsin formation by cholesterol-induced ordering of bilayer lipids.
TLDR
Values of the meta I in equilibrium with meta IItotal equilibrium constant, Keq, are calculated from the derived model-dependent rate constants, and are shown to be equivalent to those derived from rapidly acquired absorbance spectra.
Lipid headgroup and acyl chain composition modulate the MI-MII equilibrium of rhodopsin in recombinant membranes.
TLDR
The data reveal that energetic constraints on the MI and MII states imposed by egg PC-derived acyl chains can be offset by increased activity of H+ ions, and that the major effect of the membrane lipid composition is to alter the apparent pK for the MI-MII conformational equilibrium.
Primary Alcohols Modulate the Activation of the G Protein-coupled Receptor Rhodopsin by a Lipid-mediated Mechanism*
TLDR
The findings strongly support a lipid-mediated mechanism of action for alcohols on rhodopsin and, by analogy, for other G protein-coupled receptors.
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References

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Cis–trans isomerisation in rhodopsin occurs in picoseconds
IT has been believed for some time that the primary event in vision, the photochemical formation of bathorhodopsin, can be attributed to a cis–trans photoisomerisation1. Recently this model has been
Primary photochemical event in vision: proton translocation.
TLDR
The data support a model in which the formation of prelumirhodopsin involves translocation of a proton toward the Schiff base nitrogen of the retinal chromophore, which is an excellent candidate for the tunnelling process.
The molecular mechanism of excitation in visual transduction and bacteriorhodopsin.
  • A. Lewis
  • Chemistry, Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1978
TLDR
It will be demonstrated that this mechanism, which readily accounts for the photophysical and photochemical data, can be restated in terms of the Monod, Wyman, and Changeux terminology suggesting that aggregates of these pigments may function allosterically.
Temperature and wavelength effects on the photochemistry of rhodopsin, isorhodopsin, bacteriorhodopsin and their photoproducts
TLDR
It is argued that the accumulated evidence strongly favours the original suggestion of Kropf and Hubbard that the primary step involves a cis-trans isomerisation, and thus light has isomerised the chromophore from 11-cis to all-trans.
THE ACTION OF LIGHT ON RHODOPSIN.
  • R. Hubbard, A. Kropf
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1958
TLDR
Rhodopsin, a red visual pigment of vertebrate rods, is composed of the yellow carotenoid derivative, retinene, joined to the colorless protein, opsin, which bleaches in the light to a mixture of opsin and all-trans retinenes and opsIn, and the chromophore of squid rhodops in, has the neo-b (1 -cis) configuration.
Tautomeric Forms of Metarhodopsin
TLDR
The present experiments show that metarhodopsin exists in two tautomeric forms, metar Rhodopsins I and II, with λmax 478 and 380 mµ, which has been confused earlier with the final mixture of all-trans retinal and opsin, which it resembles in spectrum.
Charge stabilization mechanism in the visual and purple membrane pigments.
  • A. Warshel
  • Chemistry, Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1978
TLDR
It is suggested that the absorption of light by rhodopin and bacteriorhodopsin may be used not only for isomerization about double bonds, but also for trapping such charge-stabilized intermediates.
Bathorhodopsin intermediates from 11-cis-rhodopsin and 9-cis-rhodopsin.
TLDR
A detailed analysis of data obtained at 85 psec after excitation suggests that the bathorhodopsins generated from 11- cis- and 9-cis-rhodopsin differ in their extinction coefficients and that their absorption maxima are shifted in wavelength by about 10 nm from one another.
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