Linked Life Data

15287746

Source:http://linkedlifedata.com/resource/pubmed/id/15287746

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
31
pubmed:dateCreated
2004-8-3
pubmed:abstractText
We used differential scanning calorimetry to study the thermal denaturation of murine major histocompatibility complex class II, I-E(k), accommodating hemoglobin (Hb) peptide mutants possessing a single amino acid substitution of the chemically conserved amino acids buried in the I-Ek pocket (positions 71 and 73) and exposed to the solvent (position 72). All of the I-Ek-Hb(mut) molecules exhibited greater thermal stability at pH 5.5 than at pH 7.4, as for the I-Ek-Hb(wt) molecule, which can explain the peptide exchange function of MHC II. The thermal stability was strongly dependent on the bound peptide sequences; the I-Ek-Hb(mut) molecules were less stable than the I-Ek-Hb(wt) molecules, in good correlation with the relative affinity of each peptide for I-Ek. This supports the notion that the bound peptide is part of the completely folded MHC II molecule. The thermodynamic parameters for I-Ek-Hb(mut) folding can explain the thermodynamic origin of the stability difference, in correlation with the crystal structural analysis, and the limited contributions of the residues to the overall conformation of the I-Ek-peptide complex. We found a linear relationship between the denaturation temperature and the calorimetric enthalpy change. Thus, although the MHC II-peptide complex could have a diverse thermal stability spectrum, depending on the amino acid sequences of the bound peptides, the conformational perturbations are limited. The variations in the MHC II-peptide complex stability would function in antigen recognition by the T cell receptor by affecting the stability of the MHC II-peptide-T cell receptor ternary complex.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10186-91
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:15287746-Animals, pubmed-meshheading:15287746-Antigen Presentation, pubmed-meshheading:15287746-Aspartic Acid, pubmed-meshheading:15287746-CD4-Positive T-Lymphocytes, pubmed-meshheading:15287746-Calorimetry, Differential Scanning, pubmed-meshheading:15287746-Chromatography, Gel, pubmed-meshheading:15287746-Glutamic Acid, pubmed-meshheading:15287746-Hemoglobins, pubmed-meshheading:15287746-Histocompatibility Antigens Class II, pubmed-meshheading:15287746-Hydrogen-Ion Concentration, pubmed-meshheading:15287746-Mice, pubmed-meshheading:15287746-Mutagenesis, Site-Directed, pubmed-meshheading:15287746-Peptide Fragments, pubmed-meshheading:15287746-Protein Binding, pubmed-meshheading:15287746-Protein Conformation, pubmed-meshheading:15287746-Protein Denaturation, pubmed-meshheading:15287746-Thermodynamics
pubmed:year
2004
pubmed:articleTitle
Bound peptide-dependent thermal stability of major histocompatibility complex class II molecule I-Ek.
pubmed:affiliation
Research Institute for Biological Sciences, Tokyo University of Science, 2669, Yamazaki, Noda, Chiba 278-0022, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't