The structure and spectra of the chromophore of the visual pigments.
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Animals↗
Biomedical subjects
B Honig
Publications and source records attributed to B Honig.
Model-building of neurohypophyseal hormones.
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Amino Acid Sequence↗
Intrinsic optical activity of retinal isomers. Implications for the circular dichroism spectrum of rhodopsin.
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Binding Sites↗
Ultraviolet chromophore transitions in the rhodopsin spectrum.
Difference spectra measured at -105 degrees show two decreases in the ultraviolet absorption spectrum of rhodopsin upon bleaching that cannot be attributed to changes in protein conformation. These absorbancy decreases in rhodopsin are consistent with a cis-trans isomerization of the chromophore.
Animals↗
Implications of torsional potential of retinal isomers for visual excitation.
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Chemical Phenomena↗
Ring orientation in -ionone and retinals.
The ring orientation in beta-ionone, all-trans retinal, and 11-cis retinal, relative to that of the polyene chain, has been determined by means of semi-empirical calculations and magnetic resonance measurements of the nuclear Overhauser effect and long-range coupling constants. The experimental results yield a distorted s-cis conformation about the C(6)-C(7) "single bond", with the torsional angle in the range 30 degrees to 70 degrees . This agrees well with the semi-empirical potential function, which has a broad, rather flat minimum for angles from 40 degrees to 120 degrees . The temperature dependence of the NMR results provide confirmation for the form of the torsional potential.
Butanones↗