Summary
Four monoclonal antibodies were selected by their ability to discriminate surface-bound
from soluble fibrinogen. These antibodies reacted with insolubilized fibrinogen but
not other immobilized proteins and their reaction with surface-bound fibrinogen was
not diminished by a 100-fold excess of sotuble fibrinogen. The antibodies reacted
with the same or spatially proximal epitopes, and the recognized epitope(s) resided
within the gamma chain segment of the D domain of fibrinogen. Fab fragments of the
antibodies inhibited fibrin polymerization in a dose dependent manner, suggesting
that the epitope(s) was also exposed by the conversion of fibrinogen to fibrin. These
data indicate that adsorption of fibrinogen onto a surface induces conformational
changes and that similar changes are also evoked when fibrinogen is converted into
fibrin.
