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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
32
pubmed:dateCreated
1993-12-13
pubmed:abstractText
The monoclonal antibody C215 (IgG2a) was obtained by the immunization of BALB/c mice with the human colon adenocarcinoma cell line COLO 205 and used in the targeting of colorectal carcinomas. The partial characterization and purification of the C215 target molecule from solubilized COLO 205 membranes indicated that it is an integral membrane glycoprotein of the non-mucin type. The denatured antigen appeared as a major 40-kDa form in Western blots after SDS-polyacrylamide gel electrophoresis and migrated as a monomeric 36-kDa species after the reductive cleavage of intramolecular disulfide bridges. Using a five-step procedure, the antigen was purified 4,300-fold from COLO 205 tumors raised in nude mice to a homogeneity of 95% when assessed by capillary electrophoresis. Removal of N-linked carbohydrate by peptide:N-glycosidase treatment did not affect the visualization of the purified antigen in immunoblots but resulted in a faster migration in the SDS gels. The amino acid sequence was partially determined. Seventeen contiguous NH2-terminal amino acids were identified and coincided exactly with residues 82-98 of the GA733-2 protein cloned by Szala et al. (Szala, S., Froehlich, M., Scollon, M., Kasai, Y., Steplewske, Z., Koprowski, H., and Linnenback, A. J. (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 3542-3546). Therefore, the predicted amino acid sequence of this protein was used to prepare overlapping synthetic peptides that cover the entire extracellular domain in order to identify the C215 epitope. A likely epitope, close to the NH2 terminus and corresponding to the first distinct hydrophilic stretch after the putative signal sequence, was identified in a peptide enzyme-linked immunosorbent assay. Moreover, GA733-2 cDNA was used for the cloning of the C215 protein from COLO 205 cells and the subsequent transfection to K36.16 mouse T cell leukemia cells. The transfected cells were C215 reactive in fluorescence-activated cell sorter analysis, and a 42 kDa band was visualized in Western blots under both non-reducing and reducing conditions. Our findings indicate a close relationship between the C215 antigen and other members of the GA-733 family, some of which are currently being used as targets in clinical trials with monoclonal antibodies. The mammalian expression system described here will enable further studies into the biological role of this protein and the construction of animal models in order to develop optimal therapeutic strategies.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
268
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
24232-41
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed-meshheading:7693697-Adenocarcinoma, pubmed-meshheading:7693697-Amino Acid Sequence, pubmed-meshheading:7693697-Animals, pubmed-meshheading:7693697-Antibodies, Monoclonal, pubmed-meshheading:7693697-Antigens, Neoplasm, pubmed-meshheading:7693697-Base Sequence, pubmed-meshheading:7693697-Blotting, Western, pubmed-meshheading:7693697-Chromatography, Affinity, pubmed-meshheading:7693697-Chromatography, Gel, pubmed-meshheading:7693697-Cloning, Molecular, pubmed-meshheading:7693697-Colonic Neoplasms, pubmed-meshheading:7693697-DNA, Complementary, pubmed-meshheading:7693697-Epitopes, pubmed-meshheading:7693697-Humans, pubmed-meshheading:7693697-Membrane Glycoproteins, pubmed-meshheading:7693697-Mice, pubmed-meshheading:7693697-Mice, Nude, pubmed-meshheading:7693697-Molecular Sequence Data, pubmed-meshheading:7693697-Protein Conformation, pubmed-meshheading:7693697-Sequence Homology, Amino Acid, pubmed-meshheading:7693697-Transfection, pubmed-meshheading:7693697-Tumor Cells, Cultured
pubmed:year
1993
pubmed:articleTitle
Isolation, partial characterization, and molecular cloning of a human colon adenocarcinoma cell-surface glycoprotein recognized by the C215 mouse monoclonal antibody.
pubmed:affiliation
Department of Immunology, Kabi Pharmacia AB, Lund, Sweden.
pubmed:publicationType
Journal Article