Interactions of C1(-)-inhibitors from normal persons and patients with type
II hereditary angioneurotic edema with purified activated Hageman factor
(factor XIIa)
VH Donaldson, BH Mitchell, B Everson and OD Ratnoff
Department of Pediatrics, Children's Hospital Research Foundation,
University of Cincinnati College of Medicine 45229-2899.
Activated high molecular weight Hageman factor (75 Kd) and Hageman factor
carboxy-terminal fragments both formed complexes with purified
C1(-)-inhibitor, but the Hageman factor fragments appeared to have a higher
affinity for the C1(-)-inhibitor than activated Hageman factor. Therefore,
the clot-promoting activity of activated Hageman factor might be relatively
unimpaired if Hageman factor fragments are also present. Normal
C1(-)-inhibitor was cleaved by Hageman factor fragments. Clot-promoting
activity was not generated in Hageman factor by exposure to Hageman factor
fragments, nor was Hageman factor cleaved by Hageman factor fragments. When
Hageman factor was cleaved by streptokinase-activated plasminogen, a 40 Kd
fragment was released. In contrast to their interactions with other
proteinases, which are blocked by normal C1(-)-inhibitor, Type II
C1(-)-inhibitors from plasmas of affected members of eight different
kindred with this form of hereditary angioneurotic edema all inhibited the
specific coagulant activity of activated Hageman factor to some degree.
They did not all form complexes with activated Hageman factor that were
stable during sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
Volume 75,
Issue 4,
pp. 911-921,
02/15/1990
Copyright © 1990 by The American Society of Hematology
