Effect of light-adaptation on the photoreaction of bacteriorhodopsin from Halobacterium halobium

Ohno, Kiyoshi; Takeuchi, Yuichiro; Yoshida, Masasuke

doi:10.1016/0005-2728(77)90102-5

Cited by 89 publications

(55 citation statements)

References 19 publications

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“…No significant changes in the isomer composition were observed upon light adaptation. In BR and Anabaena sensory rhodopsin, changes in the isomer composition (36,57) upon dark adaptation give rise to characteristic difference spectra (36,58). The direction of the observed changes are opposite in BR and Anabaena sensory rhodopsin.…”

Section: Namentioning

confidence: 86%

Characterization of a Highly Efficient Blue-shifted Channelrhodopsin from the Marine Alga Platymonas subcordiformis

Govorunova

Sineshchekov

et al. 2013

Journal of Biological Chemistry

103

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Background: Channelrhodopsins are algal phototaxis receptors used in optogenetics. Results: Channel activity and photochemistry of a new channelrhodopsin (PsChR) are characterized. Conclusion: Blue-shifted PsChR has ϳ3-fold greater unitary conductance, faster recovery from excitation, and higher sodium selectivity than channelrhodopsin 2 from Chlamydomonas. Significance: These properties of PsChR facilitate further analysis of light-gated channel function and are potentially useful for optogenetics.

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Section: Namentioning

confidence: 86%

Characterization of a Highly Efficient Blue-shifted Channelrhodopsin from the Marine Alga Platymonas subcordiformis

Govorunova

Sineshchekov

et al. 2013

Journal of Biological Chemistry

103

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“…Mention has been made in the literature of the deceleration of the M412 decay by other cross-linking agents [27-301. In Table2 samples in the course of modification was found to reduce the inhibition. Because of intensified dark adaptation at high temperatures, it is difficult to say whether the reduced inhibition is associated with light adaptation or some other kind of sensitivity of the photochemical cycle intermediates [31]. However, on modification of light-adapted preparation without illumination on heating, inhibition also decreases although not so markedly.…”

Section: Resultsmentioning

confidence: 99%

The action of lanthanum ions and formaldehyde on the proton‐pumping function of bacteriorhodopsin

Drachev¹,

Drachev²,

Kaulen³

et al. 1984

European Journal of Biochemistry

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The photochemical cycle and the proton-pumping function of bacteriorhodopsin modified with lanthanum and formaldehyde has been studied. In both preparations, the M412 + BR570 transition time has been found to increase considerably. The deceleration of the photochemical cycle has been shown to be accompanied by inhibition of the millisecond phase of the photoelectrical response of bacteriorhodopsin membranes associated with phospholipidimpregnated collodion film. Photoelectrogenic activity measured with permeable ion probe in proteoliposomes was also inhibited. Effects of lanthanum were reversed by EDTA. Formation of M412 was slightly accelerated and the microsecond electrogenic phase was not affected by lanthanum and by formaldehyde. It is concluded that lanthanum, but not formaldehyde, can be used as a specific reversible inhibitor of the second half of the bacteriorhodopsin photocycle and of the associated H + uptake on the cytoplasmic side of the halobacterial membrane. Possible mechanisms of these effects are discussedBacteriorhodopsin is a bacterial proton pump that utilizes the energy of light. The properties of this protein have been investigated since 1971 [l, 21 by a variety physical and chemical methods (reviews [ 3 , 41). Its primary structure has been determined [5]. However, the mechanism of the translocation of the H+-ion remains to be elucidated.Having absorbed light, the bacteriorhodopsin molecule undergoes a cycle of photochemical conversions as a result of which H + ion(s) is(are) released on the outer side of the plasma membrane and bound on its cytoplasmic side. The central intermediate of the photochemical cycle with the absorption maximum at 412 (M412) does not have, in contrast to the initial state of bacteriorhodopsin, a proton at the Schiff base formed by retinal and E-NH,-group of the 216th lysine. The electrogenic phases of the bacteriorhodopsin cycle are revealed on pulse excitation of a planar artificial film with purple membranes adsorbed on it [6-lo]. We have established the existence of the following phases in the electric response to a light flash: (1) a negative phase; (2) a microsecond phase; (3) a millisecond phase; (4) relaxation of the potential difference that is due to the membrane capacity discharge. Phases 2 and 3 have the kinetics that is similar to that of the formation and relaxation of M412. The absence of the strict conformity between the rates of the spectral and electrical events [9, 101 testifies to the complexity of the transient states of the molecule. As it was found previously lanthanum ions inhibit the millisecond phase of the photoelectric response [6, 7, 10, 1 I] as well as the relaxation of M412 [lo, 121. The modification of purple membranes by formaldehyde [13, 141 also results in deceleration of the photochemical cycle.In this paper we have studied the deceleration of the photochemical cycle by lanthanum ions and formaldehydeAbbreviations. Mes, 4-morpholineethanesulfonic acid; FCCP, carbonylcyanide p-trifluoromethoxyphenylhydrazone; PCB-, phenyldicarbau...

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“…Spectra were obtained by using an Aviv 14DS UV-visible spectrophotometer (Aviv Associates, Lakewood, NJ). Samples were kept dark adapted to avoid an additional light-dark transition, which takes place faster than the spectra can be recorded at acidic pHs (16). The anion used in all solutions was sulfate to eliminate complications from the anion-specific formation of acid-purple membrane from the blue membrane at very low pH values (10).…”

Section: Methodsmentioning

confidence: 99%

Binding of a single divalent cation directly correlates with the blue-to-purple transition in bacteriorhodopsin.

Jonas

Ebrey

1991

Proc. Natl. Acad. Sci. U.S.A.

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We have characterized a unique divalent cation binding site on bacteriorhodopsin which controls the blue-to-purple transition in the purple membrane of Halobacterium halobium. To identify this site we first showed the correlation between the binding of one Ca2+ per bacteriorhodopsin and the amount of blue membrane converted to purple membrane. When the free Ca2+ was reduced below 1 pM, and the pH was set below 5.0 with 0.5 mM citrate, only binding to this high-affinity site was observed, and we could separate its effect from the effect of other divalent cations binding to the membrane under other conditions. Second, the titration ofpurple membrane showed that protons are taken up in two distinct steps, about 13 with a pK. of 4-5 and an additional 2 protons with a pK. of 2.75, in 5 mM MgSO4. The latter is identical to the pK. for the purple-to-blue transition in 5 mM MgSO4. Taken together, these observations strongly suggest a direct role for cations in the regulation of the bacteriorhodopsin color under normal conditions. We have also found that the intrinsic pK. for the purple-to-blue transition is about 2.05, suggesting this is the pK. of the group or groups that, when protonated, lead to the blue membrane. Previously published data can now be interpreted to suggest that the cation regulates an active site near the retinal chromophore. A binding site for the divalent cation that includes Asp-212 and interactions with the protonated Schiff base, Asp-85, Tyr-57, Tyr-185, and Arg-82 is proposed.

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Effect of light-adaptation on the photoreaction of bacteriorhodopsin from Halobacterium halobium

Cited by 89 publications

References 19 publications

Characterization of a Highly Efficient Blue-shifted Channelrhodopsin from the Marine Alga Platymonas subcordiformis

Characterization of a Highly Efficient Blue-shifted Channelrhodopsin from the Marine Alga Platymonas subcordiformis

The action of lanthanum ions and formaldehyde on the proton‐pumping function of bacteriorhodopsin

Binding of a single divalent cation directly correlates with the blue-to-purple transition in bacteriorhodopsin.

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