Linked Life Data

3373535

Source:http://linkedlifedata.com/resource/pubmed/id/3373535

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1988-6-29
pubmed:abstractText
The mass density of protein crystals can be measured in Ficoll gradients as a function of hydrostatic pressure. Carbon tetrachloride-toluene mixtures provide convenient density markers, and the compressibility of these standards is reported. Measurements on tetragonal crystals of hen egg-white lysozyme yielded densities at room temperature of 1.2367(+/- 0.0010) g cm-3 at 1 atm and 1.2586(+/- 0.0017) g cm-3 at 1000 atm (1 atm = 101,325 Pa). When combined with the unit cell dimensions at these two pressures these values lead to an estimated compression (fractional change in volume) of the crystal solvent at 1000 atm of 0.0369(+/- 0.0054). This value is comparable to that of a 0.7 M solution of NaCl. From an approximate estimate of the Donnan effect for the crystal in the 1.4 M-NaCl mother liquor, the crystal solvent contains 0.8 M-Na+ and 2.5 M-Cl-. It is concluded that the compressibility of solvent in lysozyme crystals is, within experimental error, the same as bulk solvent and does not exhibit the dramatically altered compressibility expected of an ice or glass-like solid. The crystallographically observable water sites, 151 at 1 atm and 163 at 1000 atm, showed a tendency to increase the number of hydrogen bonds made to other water sites at the expense of hydrogen bonds made to protein. The explanation for this phenomenon is presently unknown. Water sites that occur in both structures tend to have comparable temperature factors and show some tendency to follow the pressure-induced changes in protein atom positions. The compression expected for the water molecules themselves is too small to be observable at the resolution of the X-ray data collected in this study.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
200
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
401-10
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Effect of hydrostatic pressure on the solvent in crystals of hen egg-white lysozyme.
pubmed:affiliation
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.