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PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1998-7-29
pubmed:abstractText
An aspartic proteinase precursor, herein named BYC (Boophilus Yolk pro-Cathepsin) was isolated from eggs of the hard tick, Boophilus microplus. As judged by electrophoresis on sodium dodecyl sulfate polyacrylamide slab gel (SDS-PAGE), purified BYC presented 2 bands of 54 and 49 kDa, bearing the same NH2-terminal amino acid sequence. By Western blot analysis, BYC was also found in the haemolymph, indicating an extraovarian site of synthesis. Several organs were incubated in culture medium with [35S]methionine, and only the gut and fat body showed synthesis of BYC polypeptides. Protein sequencing of both the NH2-terminal and an internal sequence obtained after cyanogen bromide (CNBr) cleavage of BYC revealed homology with several aspartic proteinase precursors. Incubation at pH 3.5 resulted in autoproteolysis of BYC, which produced the mature form of the enzyme, that displayed pepstatin-sensitive hydrolytic activity against haemoglobin. Western blot analysis using anti-BYC monoclonal antibodies showed proteolytic processing of BYC during embryogenesis and suggested activation of the enzyme during development. A role of BYC in degradation of vitellin, the major yolk protein of tick eggs, is discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0031-1820
pubmed:author
pubmed:issnType
Print
pubmed:volume
116 ( Pt 6)
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
525-32
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:9651935-Adipose Tissue, pubmed-meshheading:9651935-Amino Acid Sequence, pubmed-meshheading:9651935-Animals, pubmed-meshheading:9651935-Aspartic Acid Endopeptidases, pubmed-meshheading:9651935-Blotting, Western, pubmed-meshheading:9651935-Chromatography, DEAE-Cellulose, pubmed-meshheading:9651935-Eggs, pubmed-meshheading:9651935-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:9651935-Enzyme Precursors, pubmed-meshheading:9651935-Female, pubmed-meshheading:9651935-Hemoglobins, pubmed-meshheading:9651935-Hemolymph, pubmed-meshheading:9651935-Intestines, pubmed-meshheading:9651935-Malpighian Tubules, pubmed-meshheading:9651935-Mice, pubmed-meshheading:9651935-Mice, Inbred BALB C, pubmed-meshheading:9651935-Molecular Sequence Data, pubmed-meshheading:9651935-Rabbits, pubmed-meshheading:9651935-Ticks
pubmed:year
1998
pubmed:articleTitle
Isolation of an aspartic proteinase precursor from the egg of a hard tick, Boophilus microplus.
pubmed:affiliation
Departamento de Bioquímica Médica, ICB-CCS-UFRJ, Cidade Universitária, Rio de Janeiro, RJ, Brazil. logullo@server.bioqmed.ufrj.br
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't