Linked Life Data

11800564

Source:http://linkedlifedata.com/resource/pubmed/id/11800564

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2002-1-21
pubmed:abstractText
The transferrin receptor (TfR) binds two proteins critical for iron metabolism: transferrin (Tf) and HFE, the protein mutated in hereditary hemochromatosis. Previous results demonstrated that Tf and HFE compete for binding to TfR, suggesting that Tf and HFE bind to the same or an overlapping site on TfR. TfR is a homodimer that binds one Tf per polypeptide chain (2:2, TfR/Tf stoichiometry), whereas both 2:1 and 2:2 TfR/HFE stoichiometries have been observed. In order to more fully characterize the interaction between HFE and TfR, we determined the binding stoichiometry using equilibrium gel-filtration and analytical ultracentrifugation. Both techniques indicate that a 2:2 TfR/HFE complex can form at submicromolar concentrations in solution, consistent with the hypothesis that HFE competes for Tf binding to TfR by blocking the Tf binding site rather than by exerting an allosteric effect. To determine whether the Tf and HFE binding sites on TfR overlap, residues at the HFE binding site on TfR were identified from the 2.8 A resolution HFE-TfR co-crystal structure, then mutated and tested for their effects on HFE and Tf binding. The binding affinities of soluble TfR mutants for HFE and Tf were determined using a surface plasmon resonance assay. Substitutions of five TfR residues at the HFE binding site (L619A, R629A, Y643A, G647A and F650Q) resulted in significant reductions in Tf binding affinity. The findings that both HFE and Tf form 2:2 complexes with TfR and that mutations at the HFE binding site affect Tf binding support a model in which HFE and Tf compete for overlapping binding sites on TfR.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0022-2836
pubmed:author
pubmed:copyrightInfo
Copyright 2001 Academic Press.
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
313
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
385-97
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:11800564-Binding, Competitive, pubmed-meshheading:11800564-Chromatography, Gel, pubmed-meshheading:11800564-HLA Antigens, pubmed-meshheading:11800564-Histocompatibility Antigens Class I, pubmed-meshheading:11800564-Humans, pubmed-meshheading:11800564-Kinetics, pubmed-meshheading:11800564-Ligands, pubmed-meshheading:11800564-Macromolecular Substances, pubmed-meshheading:11800564-Membrane Proteins, pubmed-meshheading:11800564-Models, Molecular, pubmed-meshheading:11800564-Molecular Weight, pubmed-meshheading:11800564-Mutation, pubmed-meshheading:11800564-Protein Conformation, pubmed-meshheading:11800564-Receptors, Transferrin, pubmed-meshheading:11800564-Surface Plasmon Resonance, pubmed-meshheading:11800564-Thermodynamics, pubmed-meshheading:11800564-Transferrin, pubmed-meshheading:11800564-Ultracentrifugation
pubmed:year
2001
pubmed:articleTitle
Mutational analysis of the transferrin receptor reveals overlapping HFE and transferrin binding sites.
pubmed:affiliation
Division of Biology 156-29 , California Institute of Technology, Pasadena, CA 91125, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't