Formation and properties of bacteriorhodopsin monomers in the non‐ionic detergents octyl‐β‐D‐glucoside and triton X‐100

Dencher, Norbert A.; Heyn, Maarten P.

doi:10.1016/0014-5793(78)80427-x

Cited by 184 publications

(148 citation statements)

References 16 publications

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“…However, upon monomerization, there is a blue shift of ϳ20 nm in the peak showing that the retinal environment changes considerably. These results are in agreement with those previously reported (25,27).…”

Section: Resultssupporting

confidence: 94%

The Role of the Native Lipids and Lattice Structure in Bacteriorhodopsin Protein Conformation and Stability as Studied by Temperature-dependent Fourier Transform-Infrared Spectroscopy

Heyes

El‐Sayed

2002

Journal of Biological Chemistry

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We report the effect of partial delipidation and monomerization on the protein conformational changes of bacteriorhodopsin (bR) as a function of temperature. Removal of up to 75% of the lipids is known to have the lattice structure of the purple membrane, albeit as a smaller unit cell, whereas treatment by Triton monomerizes bR into micelles. The effects of these modifications on the protein secondary structure is analyzed by monitoring the protein amide I and amide II bands in the Fourier transform-infrared (FT-IR) spectra. It is found that removal of the first 75% of the lipids has only a slight effect on the secondary structure at physiological temperature, whereas monomerizing bR into micelles alters the secondary structure considerably. Upon heating, the bR monomer is found to have a very low thermal stability compared with the native bR with its melting point reduced from 97 to 65°C, and the premelting transition in which the protein changes conformation in native bR at 80°C could not be observed. Also, the N-H to N-D exchange of the amide II band is effectively complete at room temperature, suggesting that there are no hydrophobic regions that are protected from the aqueous medium, possibly explaining the low thermal stability of the monomer. On the other hand, 75% delipidated bR has its melting temperature close to that of the native bR and does have a pre-melting transition, although the pre-melting transition occurs at significantly higher temperature than that of the native bR (91°C compared with 80°C) and is still reversible. Furthermore, we have also observed that the reversibility of this pre-melting transition of both native and partially delipidated bR is time-dependent and becomes irreversible upon holding at 91°C between 10 and 30 min. These results are discussed in terms of the lipid and lattice contribution to the protein thermal stability of native bR.

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Section: Resultssupporting

confidence: 94%

The Role of the Native Lipids and Lattice Structure in Bacteriorhodopsin Protein Conformation and Stability as Studied by Temperature-dependent Fourier Transform-Infrared Spectroscopy

Heyes

El‐Sayed

2002

Journal of Biological Chemistry

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“…Bacteriorhodopsin was prepared as described in [3 11. When solubiliied, bacteriorho-338 dopsin was incubated overnight with Cl& A 7 nm blue-shift in the visible absorption maximum confirmed that the pigment was solubilized [33], Light-adaptation was by extensive illu~nation with yellow light until no further absorption changes were observed. All solutions were buffered with 0.05 M MOPS, pH 7.0.…”

Section: Methodsmentioning

confidence: 86%

Light‐dependent trans to cis isomerization of the retinal in halorhodopsin

Lanyi

1984

FEBS Letters

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Flash-induced absorption changes in the near UV were determined for bacteriorhodopsin and halorhodop sin on a millisecond time scale. The difference spectrum obtained for bacteriorhodopsin was comparable to model difference spectra of tyrosine (aromatic OH deprotonated vs protonated), as found by others. The flash-induced difference spectrum for halorhodopsin, in contrast, resembled a model spectrum opbtained for trans to 13-cis isomerization of retinal in bacteriorhodopsin. A model for chloride translocation by halorhodopsin is presented, in which the retinal isomer&&on moves positive charges, which in turn modulate the affinity of a site to chloride. Halorhodopsin Retinal isomerization Tyrosine akprotonationChloride transport Flash spectroscopy

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“…Fig.2 shows the CD spectra of bR solubilized in the media (I-III) and of bR in Triton X-100, where a monomeric bR molecule keeps spectral as well as many structural features of the native chromoprotein [9]. It should be noted that in media (I) and (II) not only the CD pattern of the native bR is preserved but also the retinal-protein aldimine bond is retained.…”

Section: Resultsmentioning

confidence: 99%

¹⁹F NMR study of 5‐fluorotryptophan‐labeled bacteriorhodopsin

et al. 1987

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19F NMR and CD spectra reveal that bacteriorh~opsin as well as its S-fluorotryptophan-labeled analog solubjIized in a CH,OH-CHCI, mixture (i) retains a secondary structure of the fully active chromoprotein in the purple membrane and (ii) possesses a foided structure in which modi~cations at the Lys-216 bound retinal are sensed by sequentially remote tryptophan residues. Individual fragments isolated after limited proteolysis and NaBH&eavage of bacteriorhodopsin keep the spatial structure of the intact poiypeptide chain in the organic solvent.

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Formation and properties of bacteriorhodopsin monomers in the non‐ionic detergents octyl‐β‐D‐glucoside and triton X‐100

Cited by 184 publications

References 16 publications

The Role of the Native Lipids and Lattice Structure in Bacteriorhodopsin Protein Conformation and Stability as Studied by Temperature-dependent Fourier Transform-Infrared Spectroscopy

The Role of the Native Lipids and Lattice Structure in Bacteriorhodopsin Protein Conformation and Stability as Studied by Temperature-dependent Fourier Transform-Infrared Spectroscopy

Light‐dependent trans to cis isomerization of the retinal in halorhodopsin

¹⁹F NMR study of 5‐fluorotryptophan‐labeled bacteriorhodopsin

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Formation and properties of bacteriorhodopsin monomers in the non‐ionic detergents octyl‐β‐D‐glucoside and triton X‐100

Cited by 184 publications

References 16 publications

The Role of the Native Lipids and Lattice Structure in Bacteriorhodopsin Protein Conformation and Stability as Studied by Temperature-dependent Fourier Transform-Infrared Spectroscopy

The Role of the Native Lipids and Lattice Structure in Bacteriorhodopsin Protein Conformation and Stability as Studied by Temperature-dependent Fourier Transform-Infrared Spectroscopy

Light‐dependent trans to cis isomerization of the retinal in halorhodopsin

19F NMR study of 5‐fluorotryptophan‐labeled bacteriorhodopsin

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¹⁹F NMR study of 5‐fluorotryptophan‐labeled bacteriorhodopsin