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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1992-8-20
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pubmed:abstractText |
We functionally characterized human skin mast cell carboxypeptidase A (MC-CPA), and explored its evolutionary relationship to other carboxypeptidases to understand further the structural basis for the substrate preferences of this enzyme. Purified human skin MC-CPA displayed more activity than did bovine pancreatic carboxypeptidase A (CPA) against carboxyl-terminal leucine residues, about equal activity with phenylalanine and tyrosine residues, and no activity with tryptophan or alanine. To correlate kinetic data with structure, we isolated and sequenced a cDNA encoding MC-CPA from human skin, and directly sequenced 30% of the purified protein. These sequences agreed with that of human lung MC-CPA, and further support the evidence for a single MC-CPA gene in humans. Four amino acid replacements, resulting in a net positive change in non-hydrogen atoms in the S1' subsite of MC-CPA, were associated with less alteration in substrate specificity, relative to bovine CPA, than might be expected from studies using rat CPA1 and CPA2. We noted two consensus N-linked glycosylation sites in human MC-CPA that are not found in rat and mouse MC-CPA, or in bovine CPA; that at least one of these sites is glycosylated in vivo was verified by N-glycosidase F treatment, lentil lectin binding, and Concanavalin A-Sepharose chromatography. Evolutionary trees constructed from the known carboxypeptidase sequences suggested that MC-CPA most likely evolved from a carboxypeptidase B-like enzyme, independent of the pancreatic CPA. Thus, in the carboxypeptidase gene family, MC-CPA displays a unique genealogy and several amino acid replacements in its S1' binding pocket that result in substrate specificity quite similar to bovine CPA.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Aug
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pubmed:issn |
0022-202X
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
99
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pubmed:geneSymbol |
CPB,
MC-CPA
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
138-45
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:1629626-Amino Acid Sequence,
pubmed-meshheading:1629626-Animals,
pubmed-meshheading:1629626-Base Sequence,
pubmed-meshheading:1629626-Carboxypeptidases,
pubmed-meshheading:1629626-Cattle,
pubmed-meshheading:1629626-Glycoproteins,
pubmed-meshheading:1629626-Humans,
pubmed-meshheading:1629626-Lung,
pubmed-meshheading:1629626-Mast Cells,
pubmed-meshheading:1629626-Molecular Sequence Data,
pubmed-meshheading:1629626-Oligopeptides,
pubmed-meshheading:1629626-Pancreas,
pubmed-meshheading:1629626-Skin,
pubmed-meshheading:1629626-Species Specificity,
pubmed-meshheading:1629626-Substrate Specificity
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pubmed:year |
1992
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pubmed:articleTitle |
Human skin mast cell carboxypeptidase: functional characterization, cDNA cloning, and genealogy.
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pubmed:affiliation |
Department of Dermatology, University of California, San Francisco 94143-0536.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, Non-U.S. Gov't
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