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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 1
pubmed:dateCreated
2003-1-3
pubmed:abstractText
X-ray absorption spectroscopy (XAS), including extended X-ray absorption fine structure (EXAFS) and X-ray absorption near-edge structure (XANES) analysis, has been carried out at the Zn K edge of the N-terminal part of the integrase protein of the human immunodeficiency virus, type 2 (HIV-2), and of some zinc coordination compounds. In the presence of excess beta-mercaptoethanol, which was present in the NMR structure elucidation of the protein [Eijkelenboom et al. (1997), Curr. Biol. 7, 739-746; (2000), J. Biomol. NMR, 18, 119-28], the protein spectrum was nearly identical to that recorded in its absence. Comparison of the XANES of the protein with that of model compounds and literature data permits the conclusion that the Zn ion is four-coordinated. The major shell of the EXAFS provides evidence for a mixed (N or O as well as S) coordination sphere, while the minor shells indicate imidazole coordination. Our approach to the analysis of the EXAFS, including quantification of the imidazole by multiple scattering simulations with EXCURV92, was validated on the model compounds. An important result is that with multiple scattering simulations using restraints on the parameters of the imidazole rings the number of imidazoles and their orientation could be determined. The integrase spectra can be fitted with two sulfur ligands at 2.26 A (Debye-Waller-type factor 0.009 A(2)) and two imidazole ligands with the N atoms at 1.99 A (Debye-Waller-type factor 0.005 A(2)). The XAS-derived geometry is fully consistent with that found in the NMR structure determination and, allowing for the Volume contraction due to the temperature difference between the experiments, justifies the restraints applied in the structure calculation (Zn-S and Zn-N distances of 2.3 A and 2.0 A, respectively).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0909-0495
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
10
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
86-95
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
X-ray absorption spectroscopic studies of zinc in the N-terminal domain of HIV-2 integrase and model compounds.
pubmed:affiliation
Department of Organic Chemistry, NSR Center, University of Nijmegen, Toernooiveld, The Netherlands. mcf@sci.kun.nl
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't