[36] Isolation and purification of bovine rhodopsin

Grip, W.J. de; Daemen, F.J.M.; Bonting, S.L.

doi:10.1016/s0076-6879(80)67038-4

Cited by 101 publications

(63 citation statements)

References 47 publications

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“…Rod outer segments are isolated in dim red light by means of sucrose density gradient centrifugation [ 12] or by means of isosmotic low ionicstrength Ficoll-sucrose gradients, which better preserve some functional aspects of the outer segments [13]. The rod outer segments isolated from the gradient are sedimented at low speed (3000 × g, 15 min, 4°C).…”

Section: Discussionmentioning

confidence: 99%

“…The rod outer segments isolated from the gradient are sedimented at low speed (3000 × g, 15 min, 4°C). The sediment is cautiously resuspended in Mops-buffer (20 mM Mops, 140 mM NaC1, 5 mM KC1, 3 mM MgC12,2 mM CaCl2,1 mM dithioerythritol, 0.1 mM EDTA, pH 7.2) to a final concentration of about 1 mM in rhodopsin, as determined by its absorption at 500 nm [12].…”

Section: Discussionmentioning

confidence: 99%

“…1D). Lysis produces mainly large single-walled vesicles [12], but no change is observed in the NMR-spectra, indicating preservation of the lipid bilayer. A small isotropic component (less than 5%) derives from small vesicles, generated during lysis, washing and resuspension of the sample.…”

Section: *Phosphatidylethanolamine Amounts To About 45% Of the Phosphmentioning

confidence: 96%

“…The unbleached rod outer segment preparation ( Fig. 1A and B), which still has the stacked-disc structure as shown by electron microscopy [ 12], yields a spectrum with a number of sharp resonances superimposed on a typical broad asymmetrical resonance signal, which by comparison with model spectra [2, 3, 5, 16--19] indicates an almost perfect bilayer assemblage. This corroborates results obtained by rSntgen diffraction [20,21].…”

Section: *Phosphatidylethanolamine Amounts To About 45% Of the Phosphmentioning

confidence: 98%

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A possible role of rhodopsin in maintaining bilayer structure in the photoreceptor membrane

Grip

Drenthe

Echteld

et al. 1979

Biochimica et Biophysica Acta (BBA) - Biomembranes

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Summary31p-NMR measurements demonstrate that at 37 ° C, independent of the photolytic state of the photopigment rhodopsin, the lipids in the photoreceptormembrane are almost exclusively organised in a bilayer. In strong contrast, the 31P-NMR spectra of the extracted lipids are characteristic for the hexagonal HII phase and an isotropic phase. The isotropic phase is characterised by freeze-fracture electron microscopy as particles and pits on smooth surfaces, possibly indicating inverted micelles. These results suggest a structural role for rhodopsin in maintaining the photoreceptor membrane lipids in a bilayer configuration.It has recently been demonstrated that the lipid bilayer, while still the basic feature of biological membranes, is not the only conformational state in which the lipids in membranes can occur. 31P-NMR studies have presented strong evidence that in the endoplasmic reticulum of rat, bovine and rabbit liver the phospholipids can undergo isotropic motion, which suggests that inverted micellar structures may be present in conjunction with the bilayer [ 1 ]. Model studies of water-phospholipid mixtures show that the preferred phase depends on the type of lipid [ 2--6 ]. Under most conditions the thermodynamically most stable phase of phosphatidylcholine is the bilayer. Unsaturated phosphatidylethanolamine also prefers the bilayer conformation at lower temperatures, but at increasing temperature it undergoes a phase Abbreviation: Mops, 3-(N-morpholino)propanesulfonic acid.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: *Phosphatidylethanolamine Amounts To About 45% Of the Phosphmentioning

confidence: 96%

Section: *Phosphatidylethanolamine Amounts To About 45% Of the Phosphmentioning

confidence: 98%

See 2 more Smart Citations

A possible role of rhodopsin in maintaining bilayer structure in the photoreceptor membrane

Grip

Drenthe

Echteld

et al. 1979

Biochimica et Biophysica Acta (BBA) - Biomembranes

Self Cite

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“…82 The photochemical reaction was initiated by excitation of the retinal chromophore with 10 fs pulses centred at 520 nm, resonant with the groundstate absorption. The photo-induced dynamics were then probed by delayed pulses either in the visible region (from 500 to 720 nm, with ∼7 fs duration) or in the near-infrared region (NIR, from 820 to 1020 nm, with ∼13 fs duration), both generated by broadband OPAs.…”

Section: Pump-probe Spectroscopymentioning

confidence: 99%

Tracking the primary photoconversion events in rhodopsins by ultrafast optical spectroscopy

Polli

Rivalta

Nenov

et al. 2015

Photochem Photobiol Sci

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Opsins are a broad class of photoactive proteins, found in all classes of living beings from bacteria to higher animals, which work either as light-driven ion pumps or as visual pigments. The photoactive function in opsins is triggered by the ultrafast isomerization of the retinal chromophore around a specific carbon double bond, leading to a highly distorted, spectrally red-shifted photoproduct. Understanding, by either experimental or computational methods, the time course of this photoisomerization process is of utmost importance, both for its biological significance and because opsin proteins are the blueprint for molecular photoswitches. This paper focuses on the ultrafast 11-cis to all-trans isomerization in visual rhodopsins, and has a twofold goal: (i) to review the most recent experimental and computational efforts aimed at exposing the very early phases of photoconversion; and (ii) discuss future advanced experiments and calculations that will allow an even deeper understanding of the process. We present high time resolution pump-probe data, enabling us to follow the wavepacket motion through the conical intersection connecting excited and ground states, as well as femtosecond stimulated Raman scattering data allowing us to track the subsequent structural evolution until the first stable all-trans photoproduct is reached. We conclude by introducing computational results for two-dimensional electronic spectroscopy, which has the potential to provide even greater detail on the evolution of the electronic structure of retinal during the photoisomerization process.

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