Blood, Vol. 95 No. 7 (April 1), 2000:
pp. 2297-2303
The 
EC domain of human fibrinogen-420 is a stable
and early plasmin cleavage product
Dianne Applegate,
Lara Stoike Steben,
Kathe M. Hertzberg, and
Gerd Grieninger
From the Lindsley F. Kimball Research Institute of the New York
Blood Center, New York, NY.
Human fibrinogen-420, (
E
)2, was
isolated from plasma and evaluated for its ability to form clots and
for its susceptibility to proteolysis. Clotting parameters, including
cross-linking of subunit chains, of this subclass and of the more
abundant fibrinogen-340 ()2, were found to be
similar, suggesting little impact of the unique EC
domains of fibrinogen-420 on coagulation. Sodium dodecyl
sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of
plasmic digestion patterns revealed production from fibrinogen-420
of the conventional fibrinogen degradation products, X, Y, D, and E, to
be comparable to that from fibrinogen-340 in all respects except the
presence of at least 2 additional cleavage products that were shown by
Western blot analysis to contain the EC domain. One was
a stable fragment (ECX) comigrating with a 34-kd yeast
recombinant EC domain, and the other was an apparent precursor. Their release occurred early, before that of fragments D and
E. Two bands of the same mobility and antibody reactivity were found in
Western blots of plasma collected from patients with myocardial
infarction shortly after the initiation of thrombolytic therapy.
