R. Einarsson et L. Rydlander, TISSUE POLYPEPTIDE SPECIFIC ANTIGEN (TPS) DETECTS A SPECIFIC EPITOPE STRUCTURE ON HUMAN CYTOKERATIN, Anticancer research, 17(4B), 1997, pp. 3121-3124
A TPS-reactive protein fragment from a human colon adenocarcinoma cell
line was purified to electrophoretic homogeneity. N-terminal sequence
analysis of the purified 13 kDa protein fragment demonstrated that th
e component was a fragment of human cytokeratin 18. The M3 monoclonal
antibody (detector antibody in the TPS assay) was applied for screenin
g of an expression library. The M3-reactive phage clones were subclone
d and PCR amplified. DNA -sequence analysis revealed it to contain a n
ucleotide fragment corresponding to human cytokeratin 18. Smaller frag
ment, engineered by PCR and expressed as fusion proteins, demonstrated
that the M3 epitope is localized to human cytokeratin 18, amino acid
residues 322-340.