Linked Life Data

8440706

Source:http://linkedlifedata.com/resource/pubmed/id/8440706

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1993-3-26
pubmed:abstractText
Head-to-head association of two spectrin alpha beta heterodimers to form tetramers involves the formation of two equivalent alpha-beta complexes. The sites on the alpha subunit N-terminal region and beta subunit C-terminal region that form these alpha beta complexes have been identified using protease footprinting and direct binding assays. The existence of a similar previously hypothesized internal head-to-head alpha beta interaction in dimers was also demonstrated. The discrete regions of both subunits that are protected from proteolysis in tetramers and dimers are not due to the laterally associated subunit since head-to-head complexes of a univalent alpha peptide with a univalent beta peptide show similar protection of the same sites. These sites are unshielded immediately after monomers assemble side-to-side to form heterodimers, demonstrating that reconstituted dimers are initially in an "open" conformation. Conversion of open dimers to a closed form through formation of the internal head-to-head alpha beta association, as demonstrated by restoration of protease protection, occurred on a time scale of hours at 0 degrees C. Analysis of peptide binding affinities as well as isolation and sequence analysis of head-to-head alpha beta noncovalent complexes further defined the regions required for association on both subunits. These regions are homologous to the 106-residue repetitive motif that comprises most of both chains. An algorithm designed to improve prediction accuracy of multiple homologous motifs was used to model the conformation of spectrin repetitive motifs as well as the contact regions. In this model, the separate alpha and beta binding sites are incomplete complementary parts of a triple stranded folding unit. Formation of the alpha beta head-to-head complex produces a triple stranded conformational unit that is slightly different from other homologous motifs in the protein. Most hemolytic anemia mutations that are known to disrupt tetramer association are located in the mapped regions, including several mutations that induce a conformational change in the paired subunit.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
268
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4227-35
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Location of the human red cell spectrin tetramer binding site and detection of a related "closed" hairpin loop dimer using proteolytic footprinting.
pubmed:affiliation
Wistar Institute for Anatomy and Biology, Philadelphia, Pennsylvania 19104.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.