Purification and characterization of a human recombinant T-cell protein-tyrosine-phosphatase from a baculovirus expression system

Zander, N. F., Lorenzen, J. A., Cool, D. E., Tonks, N. K., Daum, G., Krebs, E. G., Fischer, E. H. (1991) Purification and characterization of a human recombinant T-cell protein-tyrosine-phosphatase from a baculovirus expression system. Biochemistry, 30 (28). pp. 6964-6970. ISSN 0006-2960

URL: http://www.ncbi.nlm.nih.gov/pubmed/1648966
DOI: 10.1021/bi00242a022

Abstract

A 48-kDa human T-cell protein-tyrosine-phosphatase (TC.PTPase) and a truncated form missing an 11-kDa C-terminal segment (TC-DELTA-C11.PTPase) were expressed by using the baculovirus system and characterized after extensive purification. The full-length PTPase was restricted to the particulate fraction of the cells from which it could be released by a combination of salt and detergent. The enzyme was entirely specific for phosphotyrosine residues. It displayed a low level of activity toward phosphorylated, reduced, carboxamidomethylated, and maleylated lysozyme (RCML), but was 12 times more active toward phosphorylated myelin basic protein (MBP). By contrast, the 37-kDa form localized in the soluble fraction, and its activity toward RCML was 5 times higher than that observed with MBP. The autophosphorylated cytoplasmic domain of the EGF receptor served as substrate for both enzymes. Limited proteolysis of either protein gave rise to a 33-kDa fragment displaying the substrate specificity of the truncated form. These data lend further support to the view that the C-terminal segment of the T-cell PTPase serves a regulatory function, playing an important role in the localization and substrate specificity of the enzyme.

Item Type: Paper
Uncontrolled Keywords: LEUKOCYTE COMMON ANTIGEN GROWTH-FACTOR RECEPTOR HUMAN-PLACENTA CLONING FAMILY INHIBITION KINASES VECTORS MEMBER CD45
Subjects: Investigative techniques and equipment
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > T cells
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > T cells
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > T cells

bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes > protein tyrosine phosphatase
CSHL Authors:
Communities: CSHL labs > Tonks lab
Depositing User: Matt Covey
Date Deposited: 17 Dec 2013 15:21
Last Modified: 17 Dec 2013 15:21
Related URLs:
URI: http://repository.cshl.edu/id/eprint/29085

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