Linked Life Data

12397948

Source:http://linkedlifedata.com/resource/pubmed/id/12397948

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2002-10-25
pubmed:abstractText
The dynamics of the side groups of amino acid residues and local conformational changes in the lysozyme molecule upon dehydration and rehydration of lysozyme crystals were studied by the methods of spin label, X-ray diffraction, and molecular dynamics. The His15 residue of lysozyme from chicken egg white was modified by spin label, and spin-labeled tetragonal crystals of the protein were grown. The spatial structure of the covalently bound spin label and its immediate surroundings in the lysozyme tetragonal crystal was determined. The conformation of a fragment of the lysozyme molecule with the spin label on His15, optimized by the method of molecular dynamics, closely agreed with X-ray data. It was found by the X-ray diffraction analysis that a decrease in relative humidity to 40% is accompanied by both a decrease in the unit cell volume by 27% and a change in the diffraction field of roentgenograms from 0.23 to 0.60 HM. The dehydration of spin-labeled lysozyme crystals leads to an anomalous widening of EPR peaks without changes in their position. The dehydration in the humidity range studied has a two-stage character. The decrease in humidity to 75% is accompanied by a sharp change in the parameters measured, and on further decrease in humidity to 40% they change insignificantly. The first stage is caused by the removal of the greater part of molecules of bulk water, and the second stage is due to the removal of the remaining bulk water and possible changes in the dynamics of weakly bound water molecules and their position. The simulation of experimental EPR spectra showed that the anomalous broadening of the spectrum upon dehydration is related to an increase in the dispersion of spin label orientations induced by changes in the network of hydrogen bonds generated by water molecules in the vicinity of the spin label and a possible turn (by no more than 5 degrees) of the entire protein molecule. After rehydration, the physical state of the lysozyme crystal did not return to the starting point.
pubmed:language
rus
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0006-3029
pubmed:author
pubmed:issnType
Print
pubmed:volume
47
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
795-805
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:articleTitle
[Effect of various humidity on local dynamic structure of lysozyme in a spin-labeled tetragonal crystal].
pubmed:affiliation
Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290 Russia.
pubmed:publicationType
Journal Article, English Abstract