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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
25
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pubmed:dateCreated |
1990-9-20
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pubmed:abstractText |
Fourier-transform infrared difference spectroscopy has been used to study the role of the three membrane-embedded proline residues, Pro-50, Pro-91, and Pro-186, in the structure and function of bacteriorhodopsin. All three prolines were replaced by alanine and glycine; in addition, Pro-186 was changed to valine. Difference spectra were recorded for the bR----K and bR----M photoreactions of each of these mutants and compared to those of wild-type bacteriorhodopsin. Only substitutions of Pro-186 caused significant perturbations in the frequency of the C = C and C - C stretching modes of the retinylidene chromophore. In addition, these substitutions reduced bands in the amide I and II region associated with secondary structural changes and altered signals assigned to the adjacent Tyr-185. Pro-186----Val caused the largest alterations, producing a second species similar to bR548 and nearly blocking chromophore isomerization at 78 K but not at 250 K. These results are consistent with a model of the retinal binding site in which Pro-186 and Tyr-185 are located in direct proximity to the chromophore and may be involved in linking chromophore isomerization to protein structural changes. Evidence is also found that Pro-50 may be structurally active during the bR----K transition and that substitution of this residue by glycine preserves the normal protein structural changes during the photocycle.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Asparagine,
http://linkedlifedata.com/resource/pubmed/chemical/Bacteriorhodopsins,
http://linkedlifedata.com/resource/pubmed/chemical/Proline,
http://linkedlifedata.com/resource/pubmed/chemical/Protons,
http://linkedlifedata.com/resource/pubmed/chemical/Retinal Pigments,
http://linkedlifedata.com/resource/pubmed/chemical/Schiff Bases,
http://linkedlifedata.com/resource/pubmed/chemical/Tyrosine,
http://linkedlifedata.com/resource/pubmed/chemical/Valine
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pubmed:status |
MEDLINE
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pubmed:month |
Jun
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pubmed:issn |
0006-2960
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
26
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pubmed:volume |
29
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
5954-60
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:2166567-Amino Acid Sequence,
pubmed-meshheading:2166567-Asparagine,
pubmed-meshheading:2166567-Bacteriorhodopsins,
pubmed-meshheading:2166567-Fourier Analysis,
pubmed-meshheading:2166567-Molecular Sequence Data,
pubmed-meshheading:2166567-Mutation,
pubmed-meshheading:2166567-Photochemistry,
pubmed-meshheading:2166567-Proline,
pubmed-meshheading:2166567-Protein Conformation,
pubmed-meshheading:2166567-Protons,
pubmed-meshheading:2166567-Retinal Pigments,
pubmed-meshheading:2166567-Schiff Bases,
pubmed-meshheading:2166567-Spectrophotometry, Infrared,
pubmed-meshheading:2166567-Spectrum Analysis,
pubmed-meshheading:2166567-Tyrosine,
pubmed-meshheading:2166567-Valine,
pubmed-meshheading:2166567-Vibration
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pubmed:year |
1990
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pubmed:articleTitle |
Vibrational spectroscopy of bacteriorhodopsin mutants: evidence for the interaction of proline-186 with the retinylidene chromophore.
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pubmed:affiliation |
Physics Department, Boston University, Massachusetts 02215.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, Non-U.S. Gov't
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