Linked Life Data

10841753

Source:http://linkedlifedata.com/resource/pubmed/id/10841753

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
23
pubmed:dateCreated
2000-7-20
pubmed:abstractText
Calcium (Ca(2+)) is an essential cofactor for photosynthetic oxygen evolution. Although the involvement of Ca(2+) at the oxidizing side of photosystem II of plants has been known for a long time, its ligand interactions and mode of action have remained unclear. In the study presented here, (113)Cd magic-angle spinning solid-state NMR spectroscopy is used to probe the Ca(2+)-binding site in the water-oxidizing complex of (113)Cd(2+)-substituted PS2. A single NMR signal 142 ppm downfield from Cd(ClO(4))(2).2H(2)O was recorded from Cd(2+) present at the Ca(2+)-binding site. The anisotropy of the signal is small, as indicated by the absence of spinning side bands. The signal intensity is at its maximum at a temperature of -60 degrees C. The line width of the proton signal in a WISE (wide-line separation) two-dimensional (1)H-(113)Cd NMR experiment demonstrates that the signal arises from Cd(2+) in a solid and magnetically undisturbed environment. The chemical shift, the small anisotropy, and the narrow line of the (113)Cd NMR signal provide convincing evidence for a 6-fold coordination, which is achieved partially by oxygen and partially by nitrogen or chlorine atoms in otherwise a symmetric octahedral environment. The absence of a (113)Cd signal below -70 degrees C suggests that the Ca(2+)-binding site is close enough to the tetramanganese cluster to be affected by its electron spin state. To our knowledge, this is the first report for the application of solid-state NMR in the study of the membrane-bound PS2 protein complex.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
39
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6751-5
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Exploring the calcium-binding site in photosystem II membranes by solid-state (113)Cd NMR.
pubmed:affiliation
Leiden Institute of Chemistry, Gorlaeus Laboratoria, University of Leiden, 2300 RA Leiden, The Netherlands.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't