A monoclonal antibody, specific for human fibrinogen, fibrinopeptide A-
containing fragments and not reacting with free fibrinopeptide A
PW Koppert, CM Huijsmans and W Nieuwenhuizen
Spleen cells of BALB/c mice, immunized with fragments Y of normal human
fibrinogen, were fused with P3 X 63 Ag 8653 myeloma cells. A clone was
found which produces monoclonal antibodies (Mab-Y18) of the IgM kappa type.
Mab-Y18 is immunoreactive with normal human fibrinogen, and its fragments
X, Y, N-terminal disulphide knot, A alpha-chain, and A alpha stretch 1-51.
The immunoreactivity with these same fragments disappears upon treatment
with thrombin or arvin. This strongly suggests that fibrinopeptide A is an
essential component of the Mab-Y18 epitope. This is supported by the
finding that Mab-Y18 prolongs the thrombin and arvin clotting times of
human fibrinogen by inhibition of the fibrinopeptide A release. More
detailed information about the nature of the Mab-Y18 epitope was obtained
from studies with genetic variants of human fibrinogen (especially
fibrinogen Metz) and with fibrinogens from other mammalian species. These
studies show that amino acid residue A alpha 16 (arginine) of
fibrinopeptide A is essential for the Mab-Y18 epitope. Mab-Y18 does not
react with free fibrinopeptide A.
Volume 66,
Issue 3,
pp. 503-507,
09/01/1985
Copyright © 1985 by The American Society of Hematology
