Linked Life Data

820572

Source:http://linkedlifedata.com/resource/pubmed/id/820572

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1976-10-1
pubmed:abstractText
Immunoglobulin light chains are examples of single polypeptide chains synthesized under the control of two genes. The three-dimensional structure of a human (Mcg) lambda-type chain (Bence-Jones) dimer supports the hypothesis of a common primordial gene for the amino ("variable" or V) and carboxyl ("constant" or C) halves of each monomer. However, sequence homologies have been obscurred by divergent evolution of the V and C regions ("domains"). The types of evolutionary changes that have occurred in the domain can be surmised by a comparison of the sequences, using the three-dimensional structures as a basis for alignment. Despite substantial differences in sequences, the hydrophobic character of key internal sites has been maintained in each domain. Regions present in only one domain are situated in position appropriate for their functions, but not deleterious to the general structural integrity of a common fold. The divergence of the V and C domains can be interpreted in terms of rotational allomerism. The cylinders of beta-pleated sheets have rotated in such a way that homologous regions in the two domains perform different functions in their interactions with a second molecule of light or heavy chain. These regions include complementarity-determining sites for antigen binding in the V domains and crossover sites stabilizing dimer formation in the C domains. Differences in surface properties between the V1-V2 and C1-C2 dimeric modules may partially explain why the V regions have been implicated in the formation of amyloid fibrils and in the characteristic thermal behavior of Bence-Jones proteins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0014-9446
pubmed:author
pubmed:issnType
Print
pubmed:volume
35
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2119-23
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1976
pubmed:articleTitle
Conformational isomerism, rotational allomerism, and divergent evolution in immunoglobulin light chains.
pubmed:publicationType
Journal Article