Linked Life Data

10407071

Source:http://linkedlifedata.com/resource/pubmed/id/10407071

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-9-3
pubmed:abstractText
To date, although at least 75 different PTPases (protein-tyrosine-phosphate-phosphohydrolase, EC 3.1.3.48) have been identified, those detected in platelets are rather scarce. Based on previous results from our laboratory, we investigated the existence of new PTPases in platelets. Triton X-114 phase partitioning of Triton X-100-solubilized human and sheep platelet membranes allowed PTPase to be recovered in the detergent-rich (40-35%, respectively) and -poor phases (60-65%, respectively). Sedimentation analyses of both phases from the sheep species revealed hydrophilic 6S and 3.7S, and amphiphilic 7.5S and 10.3S PTPase forms. Sedimentation analyses of human platelet membrane-associated or cytosolic PTPase revealed hydrophilic 6.7S and 4.3S, and amphiphilic 5.5S and 10.8S forms, or hydrophilic 4S, 5.9S and 6.9S forms, respectively. Western blot analysis using monoclonal antibodies (MoAb) against human PTP1B, PTP1C, PTP1D and RPTPalpha (mouse anti-human PTPase MoAbs) showed that RPTPalpha was not present in platelets and that the PTP1C type and PTP1D type (but probably not the PTP1B type) were expressed in sheep species. Immunoblots also revealed that all PTPases detected were mainly membrane-associated, with similar percentages of cellular distribution in both species. All PTPases were mainly recovered in the detergent-poor phases from the Triton X-114 phase partitioning, although PTP1D from human species was also significantly present (30%) in the detergent-rich phase. Additionally, all PTPases sedimented within the same PTPase peak in sucrose gradients (sedimentation coefficients around 4S). These findings indicate that amphiphilic and hydrophilic PTPases different from PTP1B, PTP1C, PTP1D or RPTPalpha, with higher sedimentation coefficients and with higher activity when O-phosphotyrosine or a synthetic peptide phosphorylated on tyrosine were used as substrates, are present in platelets.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
1419
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
195-206
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Amphiphilic and hydrophilic nature of sheep and human platelet phosphotyrosine phosphatase forms.
pubmed:affiliation
Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, Edificio Departamental (Laboratorio 106), Plaza Doctores de la Reina s/n, E-37007, Salamanca, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't