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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
36
|
pubmed:dateCreated |
1990-2-1
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pubmed:abstractText |
Seven imperfect repeats of a 40-amino acid cysteine-rich sequence constitute the ligand binding domain of the low density lipoprotein (LDL) receptor. To assess the contribution of each repeat, three site-directed mutations were made individually in each repeat: 1) deletion of the repeat, 2) substitution of a conserved isoleucine with aspartic acid, and 3) substitution of a conserved aspartic acid with tyrosine. cDNAs containing these mutations were transfected into simian COS cells and assayed for their ability to bind LDL, which contains a 500-kDa protein ligand (apoB-100), and beta-migrating very low density lipoprotein (beta-VLDL), which contains multiple copies of a 33-kDa ligand (apoE). The results showed that binding of the two ligands required different combinations of repeats. LDL binding required repeats 3-7; deletion of any one of these repeats markedly reduced LDL binding. In contrast, beta-migrating very low density lipoprotein binding was insensitive to the loss of any single repeat with the important exception of repeat 5, whose loss reduced binding by 60%. The same effects were obtained when each of the repeats was altered by either of the two substitution mutations. The current findings suggest that a multiplicity of cysteine-rich repeats may allow a single protein to bind several different protein ligands by employing different combinations of repeats.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical | |
pubmed:status |
MEDLINE
|
pubmed:month |
Dec
|
pubmed:issn |
0021-9258
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:day |
25
|
pubmed:volume |
264
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
21682-8
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:2600087-Amino Acid Sequence,
pubmed-meshheading:2600087-Animals,
pubmed-meshheading:2600087-Cell Line,
pubmed-meshheading:2600087-Cysteine,
pubmed-meshheading:2600087-DNA,
pubmed-meshheading:2600087-Genetic Vectors,
pubmed-meshheading:2600087-Humans,
pubmed-meshheading:2600087-Kinetics,
pubmed-meshheading:2600087-Ligands,
pubmed-meshheading:2600087-Mutation,
pubmed-meshheading:2600087-Plasmids,
pubmed-meshheading:2600087-Receptors, LDL,
pubmed-meshheading:2600087-Repetitive Sequences, Nucleic Acid,
pubmed-meshheading:2600087-Sequence Homology, Nucleic Acid,
pubmed-meshheading:2600087-Transfection
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pubmed:year |
1989
|
pubmed:articleTitle |
Different combinations of cysteine-rich repeats mediate binding of low density lipoprotein receptor to two different proteins.
|
pubmed:affiliation |
Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas 75235.
|
pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
|