Linked Life Data

2397202

Source:http://linkedlifedata.com/resource/pubmed/id/2397202

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
28
pubmed:dateCreated
1990-10-12
pubmed:abstractText
beta-Crystallins are complex eye lens proteins made up of several related basic and acidic subunits that combine to form differently sized oligomers each displaying extensive polydispersity. As the sequences are homologous to the X-ray-determined bilobal structure of gamma-crystallin, beta-subunits are visualized as having a similar structure with additional N- and C-terminal extensions. Two basic (beta B2 and beta B3) and two acidic (beta A3 and beta A4) subunits have been isolated in deaggregating media, refolded, and reassociated in various combinations to determine which components favor dimers or higher oligomers. Homopolymers were compared with beta B2 homodimer in terms of charge, using Mono Q fast protein liquid chromatography, and size, using Superose 12 chromatography. Heterooligomeric formations were monitored by their intermediate charge properties compared with homooligomers. beta B2 associates with either beta B3- or beta A4-forming heterodimers whereas a larger oligomer is formed with beta A3. Naturally occurring beta-crystallin oligomers were analyzed by Mono Q chromatography and PhastGel electrophoresis. Whereas beta B2, beta B3, and beta A4 can each be reassociated to homodimers, beta A4 dimers are not found in native beta-crystallins. beta B2-beta A3 is a major component of intermediate-sized beta L1-crystallin and is absent from dimeric beta L2-crystallin. It is suggested that the pH dependence of the size of beta L1-crystallin is due to a dimer to tetramer equilibrium. By following dimer interactions using Superose 12 chromatography, beta B2-beta A4 was shown to interact with beta B2-beta A3. A model of beta-crystallin structure is proposed based on beta-subunits forming dimers with the next level of organization requiring an acidic subunit, beta A3, with a long N-terminal extension.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6592-9
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Quaternary interactions in eye lens beta-crystallins: basic and acidic subunits of beta-crystallins favor heterologous association.
pubmed:affiliation
Department of Crystallography, Birkbeck College, London, U.K.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't