Linked Life Data

1445908

Source:http://linkedlifedata.com/resource/pubmed/id/1445908

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
47
pubmed:dateCreated
1992-12-30
pubmed:abstractText
The absorption spectrum of light-adapted purple membrane in 3 M KCl is dependent on temperature even in the room temperature region. Temperature-induced difference spectra at various pH values suggested that the trans isomer of bacteriorhodopsin, bR570, is in thermal and/or photodynamic equilibrium with several different conformers. The major second conformer occurring at neutral pH had the same spectroscopic properties as the 13-cis isomer, and its content at 35 degrees C was estimated to be more than 20%. Heterogeneity in the protein conformation became more significant above pH8, where temperature-induced difference spectra exhibited a negative peak at 580 nm and a positive peak at 296 nm. This absorption change is very similar to that observed upon the formation of the N intermediate, suggesting that an N-like conformer occurs at high pH and temperature. A significant temperature dependence was also seen in the M decay kinetics at high pH, which were described by two decay components; i.e., the fast decaying M (Mf) was predominant at low temperature, but the amplitude of the slow component (M(s)) increased with increasing temperature. It is suggested that M(s) is generated upon excitation of the N-like conformer, in which the residue (Asp-96) usually acting as a proton donor to the Schiff base is deprotonated. The N-like conformer could be N itself, because M(s) was enhanced when N was accumulated by background light. A strong correlation between the amplitude of M(s) and the concentration of N was also revealed by the accumulation kinetics of Mf, M(s), and N after the onset of continuous actinic light.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11740-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Photoreaction of bacteriorhodopsin at high pH: origins of the slow decay component of M.
pubmed:affiliation
Institute of Physical and Chemical Research (RIKEN), Saitama, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't