Linked Life Data

12112018

Source:http://linkedlifedata.com/resource/pubmed/id/12112018

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2002-7-11
pubmed:abstractText
PTP-MEG2 is an intracellular protein tyrosine phosphatase with a putative lipid-binding domain at the N-terminus. The present study reports expression, purification, and characterization of the full-length form of the enzyme plus a truncated form containing the catalytic domain alone. Full-length PTP-MEG2 was expressed with an adenovirus system and purified from cytosolic extracts of human 293 cells infected with the recombinant adenovirus. The purification scheme included chromatographic separation of cytosolic extracts on fast flow Q-Sepharose, heparin-agarose, l-histidyldiazobenzylphosphonic acid agarose, and hydroxylapatite. The enrichment of PTP-MEG2 from the cytosol was about 120-fold. The truncated form of PTP-MEG2 was expressed in E. coli cells as a non-fusion protein and purified by using a chromatographic procedure similar to that used for the full-length enzyme. The purified full-length and truncated enzymes showed single polypeptide bands on SDS-polyacrylamide gel electrophoresis under reducing conditions and behaved as monomers on gel exclusion chromatography. With para-nitrophenylphosphate and phosphotyrosine as substrates, both forms of the enzyme exhibited classical Michaelis-Menten kinetics. Their responses to pH, ionic strength, metal ions, and protein phosphatase inhibitors are similar to those observed with other characterized tyrosine phosphatases. Compared with full-length PTP-MEG2, the truncated DeltaPTP-MEG2 displayed significantly higher V(max) and lower K(m) values, suggesting that the N-terminal putative lipid-binding domain may have an inhibitory role. The full-length and truncated forms of PTP-MEG2 were also expressed as GST fusion proteins in E. coli cells and purified to near homogeneity through affinity columns. However, the specific phosphatase activities of the GST fusion proteins were 10-25-fold below those obtained with the correspondent non-fusion proteins.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0730-2312
pubmed:author
pubmed:copyrightInfo
Copyright 2002 Wiley-Liss, Inc.
pubmed:issnType
Print
pubmed:volume
86
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
79-89
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Purification and characterization of protein tyrosine phosphatase PTP-MEG2.
pubmed:affiliation
Division of Hematology/Oncology, Department of Medicine, Department of Veterans Affairs Medical Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37232, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.