Post-translational modifications of recombinant human tissue factor.

Recombinant human tissue factor (rTF) purified from transfected mammalian cells is a glycoprotein that contains N-linked, but not O-linked oligosaccharides. Two of the three potential N-linked sites in the extracellular portion are fully glycosylated, while one site is approximately 90% utilized. These sites have complex-type oligosaccharides attached. The potential N-linked site in the cytoplasmic domain near the C-terminus is not glycosylated. Characterization of the tryptic map of rTF confirmed most of the proposed amino acid sequence. In addition, the disulfide bonds (between Cys-49 and Cys-57 and between Cys-186 and Cys-209) were demonstrated by FAB-MS analysis of cysteine-containing fragments obtained from the tryptic map.