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Groesbeek M, Kirillova YG, Boeff R, Lugtenburg J. Synthesis of six novel retinals and their interaction with bacterioopsin. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/recl.19941130107] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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El-Saeed SM, Farag RK, Abdul-Raouf ME, Abdel-Azim AAA. Synthesis and Characterization of Novel Crude Oil Dispersants Based on Ethoxylated Schiff Base. INT J POLYM MATER PO 2008. [DOI: 10.1080/00914030802089385] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Gillespie NB, Ren L, Ramos L, Daniel H, Dews D, Utzat KA, Stuart JA, Buck CH, Birge RR. Characterization and Photochemistry of 13-Desmethyl Bacteriorhodopsin. J Phys Chem B 2005; 109:16142-52. [PMID: 16853051 PMCID: PMC1513633 DOI: 10.1021/jp052124+] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The photochemistry of the 13-desmethyl (DM) analogue of bacteriorhodopsin (BR) is examined by using spectroscopy, molecular orbital theory, and chromophore extraction followed by conformational analysis. The removal of the 13-methyl group permits the direct photochemical formation of a thermally stable, photochemically reversible state, P1(DM) (lambda(max) = 525 nm), which can be generated efficiently by exciting the resting state, bR(DM) with yellow or red light (lambda > 590 nm). Chromophore extraction analysis reveals that the retinal configuration in P1(DM) is 9-cis, identical to that of the retinal configuration in the native BR P1 state. Fourier transform infrared and Raman experiments on P1(DM) indicate an anti configuration around the C15=N bond, as would be expected of an O-state photoproduct. However, low-temperature spectroscopy and ambient, time-resolved studies indicate that the P1(DM) state forms primarily via thermal relaxation from the L(D)(DM) state. Theoretical studies on the BR binding site show that 13-dm retinal is capable of isomerizing into a 9-cis configuration with minimal steric hindrance from surrounding residues, in contrast to the native chromophore in which surrounding residues significantly obstruct the corresponding motion. Analysis of the photokinetic experiments indicates that the Arrhenius activation energy of the bR(DM) --> P1(DM) transition in 13-dm-BR is less than 0.6 kcal/mol (vs 22 +/-5 kcal/mol measured for the bR --> P (P1 and P2) reaction in 85:15 glycerol:water suspensions of wild type). Consequently, the P1(DM) state in 13-dm-BR can form directly from all-trans, 15-anti intermediates (bR(DM) and O(DM)) or all-trans, 15-syn (K(D)(DM)/L(D)(DM)) intermediates. This study demonstrates that the 13-methyl group, and its interactions with nearby binding site residues, is primarily responsible for channeling one-photon photochemical and thermal reactions and is limited to the all-trans and 13-cis species interconversions in the native protein.
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Affiliation(s)
- Nathan B. Gillespie
- Departments of Chemistry and of Molecular and Cell Biology, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269-3060
- W. M. Keck Center for Molecular Electronics and Department of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13244-4100
| | - Lei Ren
- Departments of Chemistry and of Molecular and Cell Biology, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269-3060
- W. M. Keck Center for Molecular Electronics and Department of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13244-4100
| | - Lavoisier Ramos
- Departments of Chemistry and of Molecular and Cell Biology, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269-3060
| | - Heather Daniel
- Departments of Chemistry and of Molecular and Cell Biology, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269-3060
| | - Deborah Dews
- Departments of Chemistry and of Molecular and Cell Biology, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269-3060
| | - Karissa A. Utzat
- Departments of Chemistry and of Molecular and Cell Biology, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269-3060
| | - Jeffrey A. Stuart
- W. M. Keck Center for Molecular Electronics and Department of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13244-4100
| | - Charles H. Buck
- W. M. Keck Center for Molecular Electronics and Department of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13244-4100
| | - Robert R. Birge
- Departments of Chemistry and of Molecular and Cell Biology, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269-3060
- *Address correspondence to this author (
) corresponding author: Robert R. Birge, Department of Chemistry, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269-3060: 860-486-6720; Fax(860-486-2981);
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Yan B, Xie A, Nienhaus GU, Katsuta Y, Spudich JL. Steric constraints in the retinal binding pocket of sensory rhodopsin I. Biochemistry 1993; 32:10224-32. [PMID: 8399150 DOI: 10.1021/bi00089a044] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Steric constraints in the retinal binding pocket of sensory rhodopsin I (SR-I) are analyzed by studying effects of sample temperature and retinal analogs. The flash-induced yield of the earliest detected intermediate S610, which corresponds to the K intermediate in the bacteriorhodopsin (BR) photocycle, decreases below 220 K and reaches zero at 100 K, while K formation is independent of temperature. The reduced S610 formation at low temperatures indicates a more restricted retinal binding pocket in SR-I during primary photochemical events. Introduction of bulky substituents on the retinal polyene chain in four retinal analogs greatly retards or blocks the final step of chromophore binding to the apoprotein of SR-I. Except for the 14-methyl substitution, these modifications exhibit little or no effect on chromophore binding to BR apoprotein. These results corroborate that the retinal polyene chain binding domain in SR-I is more sterically constrained than that of the retinal pocket in BR. Deletion of the beta-ionone ring renders the analog SR-I pigments nonfunctional, as does deletion of the 13-methyl group, but the corresponding BR analogs are both photochemically and physiologically active. In contrast to the corresponding BR analog, photolysis of the analog SR-I reconstituted with 13-desmethylretinal does not produce an S610-like intermediate at room temperature. The above results and the previous findings that protein constraints inhibit the accommodation of a stable 13-cis-retinal configuration in SR-I suggest a model in which the 13-methyl group functions as a fulcrum to permit movement of one or both ends of retinal to overcome an energy barrier against isomerization.
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Affiliation(s)
- B Yan
- Department of Microbiology and Molecular Genetics, University of Texas Medical School, Houston 77030
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Heyn MP, Otto H. PHOTOSELECTION AND TRANSIENT LINEAR DICHROISM WITH ORIENTED IMMOBILIZED PURPLE MEMBRANES: EVIDENCE FOR MOTION OF THE C(20)-METHYL GROUP OF THE CHROMOPHORE TOWARDS THE CYTOPLASMIC SIDE OF THE MEMBRANE. Photochem Photobiol 1992. [DOI: 10.1111/j.1751-1097.1992.tb09734.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Spudich JL, Bogomolni RA. Sensory rhodopsin I: receptor activation and signal relay. J Bioenerg Biomembr 1992; 24:193-200. [PMID: 1526961 DOI: 10.1007/bf00762677] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Recent progress is summarized on the mechanism of phototransduction by sensory rhodopsin I (SR-I), a phototaxis receptor in Halobacterium halobium. Two aspects are emphasized: (i) The coupling of retinal isomerization to protein conformational changes. Retinal analogs have been used to probe chromophore-apoprotein interactions during the receptor activation process. One of the most important results is the finding of a steric trigger deriving from the interaction of residues on the protein with a methyl group near the isomerizing bond of the retinal (at carbon 13). Recent work on molecular genetic methods to further probe structure/function includes the synthesis and expression of an SR-I apoprotein gene designed for residue replacements by cassette mutagenesis, and transformation of an H. halobium mutant lacking all retinylidene proteins known in this species to SR-I+ and bacteriorhodopsin (BR)+. (ii) The relay of the SR-I signal to a post-receptor component. A carboxylmethylated protein ("MPP-I") associated with SR-I and found in the H. halobium membrane exhibits homology with the signaling domain of eubacterial chemotaxis transducers (e.g., Escherichia coli Tar, Tsr, and Trg proteins), suggesting a model based on SR-I----MPP-I signal relay.
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Affiliation(s)
- J L Spudich
- Department of Microbiology and Molecular Genetics, University of Texas Medical School, Houston 77030
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Danshina SV, Drachev AL, Drachev LA, Eremin SV, Kaulen AD, Khitrina LV, Mitsner BI. C(13)-substituted bacteriorhodopsin analogs. Arch Biochem Biophys 1990; 279:225-31. [PMID: 2350173 DOI: 10.1016/0003-9861(90)90485-h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
13-Ethyl-, 13-isopropyl-, 13-tert-butyl-, 13-phenyl-, 13-alpha-naphthyl-, and 13-demethyl-retinals were synthesized and incubated with bacterioopsin (bO) to give the corresponding bacteriorhodopsin (bR) analogs. The capability of the 13-tert-butyl- and 13-alpha-naphthyl-bRs to exist and to photocycle shows that apparently around C(13) of the chromophore there lies a large enough cavity. A study of the light-induced conversions of the artificial pigments prepared has shown that the introduction at position 13 of the chromophore of the hydrocarbon substituents bulkier than that of the natural bR diminished the amplitudes of the electric photoresponses. Bulky C(13)-substituents or absence of substitution at that position decelerated the relaxation of the M-intermediates and disturbed the 13-cis-in equilibrium all-trans-isomerization.
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Affiliation(s)
- S V Danshina
- A. N. Belozersky Laboratory of Molecular Biology and Bioorganic Chemistry, Moscow, USSR
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Soppa J, Otomo J, Straub J, Tittor J, Meeßen S, Oesterhelt D. Bacteriorhodopsin Mutants of Halobacterium sp. GRB. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)51594-5] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Gärtner W, Oesterhelt D. Methoxyretinals in bacteriorhodopsin. Absorption maxima, cis-trans isomerization and retinal protein interaction. EUROPEAN JOURNAL OF BIOCHEMISTRY 1988; 176:641-8. [PMID: 2844533 DOI: 10.1111/j.1432-1033.1988.tb14325.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Analogue bacteriorhodopsins (BRs) were reconstituted from bacterioopsin and 9-, 11-, or 13-methoxyretinals or their demethyl derivatives, respectively. In organic solvents the retinals occur as cis isomers of the respective double bonds carrying the methoxy group. 9-Methoxyretinal, present as the 9-cis isomer, does not form an analogue BR with bacterioopsin in the dark. Upon illumination, a BR is produced with an absorbance maximum at 560 nm. This compound is thermally unstable, and converts back into the 9-cis-containing complex (lambda max = 410 nm) in the dark. Removal of the 13-methyl group from this compound (= 9-methoxy 13-demethyl retinal) does not change the 9-cis configuration of the free retinal, but allows the reconstitution of a thermally stable chromoprotein absorbing around 500 nm with a proton translocation rate of about 10% of the BR value, comparable to the 13-demethyl BR value [Gärtner, W., Towner, P., Hopf, H. & Oesterhelt, D. (1983) Biochemistry 22, 2637-2644]. 11-Methoxy BRs (13-demethyl and 9,13-didemethyl) absorb around 530 nm and are inactive. 13-Methoxy retinal (13-cis isomer) reconstitutes a chromoprotein with an absorbance maximum at 515 nm, which can be photoconverted to a thermostable 460-nm-absorbing complex. For the 515-nm-absorbing species of 13-methoxy BR a light-induced proton translocation was not detected in measurements with cell vesicles (detection of pH changes in the vesicle preparation). Only by photocurrent measurements in a bilayer experiment could a very diminished photocurrent be detected, about 1-2% of BR, [Fendler et al. (1987) Biochim. Biophys. Acta 893, 60-68]. The reconstitution rate of 13-methoxy BR from 13-methoxy retinal and bacterioopsin is slower by a factor of 40 compared to 13-ethyl BR, although both substituents are of similar size. The position 13 of retinal was found to be most sensitive for regulation of the absorption maximum and the formation and stability of the all-trans isomer, which is the active form for light-induced proton translocation. The results suggest that an electronic interaction with a charged residue of the binding site exists around position 13 of retinal, which is disturbed when a methoxy group replaces the methyl or ethyl group at that position. This electronic interaction is essential for maintaining the active all-trans configuration of retinal.
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Affiliation(s)
- W Gärtner
- Institut für Biologie I (Zoologie), Freiburg, Federal Republic of Germany
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