Linked Life Data

17555765

Source:http://linkedlifedata.com/resource/pubmed/id/17555765

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2007-6-18
pubmed:abstractText
The hydrogen bonding of polar side-chains has emerged as an important theme for membrane protein interactions. The crystal structure of the dimeric state of the transmembrane beta-barrel protein outer membrane phospholipase A (OMPLA) revealed an intermolecular hydrogen bond mediated by a highly conserved glutamine side-chain (Q94). It has been shown that the introduction of a polar residue can drive the association of model helices, and by extension it was presumed that the glutamine hydrogen bond played a key role in stabilizing the OMPLA dimer. However, a thermodynamic investigation using sedimentation equilibrium ultracentrifugation in detergent micelles reveals that the hydrogen bond plays only a very modest role in stabilizing the dimer. The Q94 side-chain is hydrogen bonded intramolecularly to residues Y92 and S96, but amino acid substitutions at these positions suggest these intramolecular interactions are not responsible for attenuating the strength of the intermolecular Q94 hydrogen bond. Other substitutions suggested that hydration of the local environment around Q94 may be responsible for the modest strength of the hydrogen bond. Heat inactivation experiments with the variants suggest that the Y92-Q94-S96 network may instead be important for thermal stability of the monomer. These results highlight the context dependence and broad range of interactions that can be mediated by polar residues in membrane proteins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
370
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
912-24
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
The role of a hydrogen bonding network in the transmembrane beta-barrel OMPLA.
pubmed:affiliation
T.C. Jenkins Department of Biophysics, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.