Linked Life Data

1460279

Source:http://linkedlifedata.com/resource/pubmed/id/1460279

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1993-1-14
pubmed:abstractText
We have previously described the isolation of two hybridoma variants secreting higher avidity IgM (D5 and 7F5), starting from the E11 hybridoma cell line, which produces an antibody specific for the A Ag of the ABO blood group system. In order to explain at the molecular level this increased reactivity, cDNA encoding the H and L chains of the E11, D5, and 7F5 mAb were cloned and sequenced. Comparison of the nucleotide sequences showed a single point mutation in each of the two mAb produced by the hybridoma variants. The mutations were both located in the H chain C region and caused a Ser to Phe substitution at position 565 in the D5 mAb and a Asn to Tyr substitution at position 563 in the 7F5 mAb. Both substitutions modified the consensus glycosylation sequence (Asn-X-Ser/Thr) located in the tail piece of the secretory mu-chain. The absence of glycosylation at this site was confirmed by CNBr cleavage of the [14C]mannose-labeled mAb. The two single point mutations were solely responsible for the increased avidity of the antibodies, as confirmed by site-directed mutagenesis of the E11 mu-chain and serologic analysis of the mutated E11 antibodies. We conclude that the absence of glycosylation at Asn 563 is responsible for the increased avidity of the mutant, possibly by altering the quaternary structure of the IgM polymer. To our knowledge, this is the first report that point mutations in the H chain C region can influence the reactivity of IgM mAb.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
149
pubmed:owner
NLM
pubmed:authorsComplete
N
pubmed:pagination
3889-93
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Increased avidity of mutant IgM antibodies caused by the absence of COOH-terminal glycosylation of the mu H chain.
pubmed:affiliation
Canadian Red Cross Society, Blood Services, Quebec City, P. Qc.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't