Linked Life Data

16981717

Source:http://linkedlifedata.com/resource/pubmed/id/16981717

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
38
pubmed:dateCreated
2006-9-19
pubmed:abstractText
The uptake of chloride, bromide, iodide, nitrate, and azide by anion-depleted blue halorhodopsin from Natronobacterium pharaonis has been followed by FTIR difference spectroscopy using an ATR sampling device. The spectra are compared with the spectrum of the O intermediate obtained by time-resolved FTIR studies of the photocycle. It is demonstrated that anion-free blue halorhodopsin can be identified with the O intermediate and, thus, that the decay of O is due to the passive uptake of the anion. The great similarity of the anion-binding spectra and their identity in the case of the monoatomic anions indicate a rather unspecific binding site for the different anions dominated by electrostatic interactions. Comparing spectra obtained with 15N nitrate and unlabeled nitrate, the NO-stretching bands could be identified. The small splitting and the small IR intensity of those bands indicate a rather nonpolar binding site with a rather isotropic influence on the nitrate, in contrast to aqueous nitrate. In further experiments on the photocycle of blue halorhodopsin, the all-trans --> 13-cis isomerization can be clearly identified. Up to 100 micros, the isomerization-induced structural changes deduced from amide I changes are similar to those occurring during the anion-transporting photocycle. Compared to these, the molecular changes involved in the release and their reversion during the uptake of anions are considerably larger. They can be reached via two pathways: (1) by reducing the anion concentration and (2) transiently during the anion-transporting photocycle with the formation of the precursor of O with O conformation. Consequences of the anion transport mechanism are discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
45
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11578-88
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Anion uptake in halorhodopsin from Natromonas pharaonis studied by FTIR spectroscopy: consequences for the anion transport mechanism.
pubmed:affiliation
Sektion Biophysik, Institut für Molekulare Medizin und Zellforschung, Albert-Ludwigs-Universität, 79104 Freiburg, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't