Interactions of Plasma Kallikrein and Cis With Normal and Dysfunctional Cl-Inhibitor Proteins From Patients With Hereditary Angioneurotic Edema: Analytic Gel Studies

Purified preparations of normal Cl-inhibitor (Ci-INH) formed high mol wt complexes with plasma kallikrein that were stable during sodium dodecyl sulfate (SDS)-gel electrophoresis, but most of the dysfunctional Cl -INH proteins isolated from plasma of patients with type II hereditary angioneurotic edema (HANE) did not. Two of eight dysfunctional Cl -INH proteins were cleaved to lower mol wt forms that were not seen following the reaction of normal Cl -INH with equimolar amounts. or less. of plasmakallikrein. Only the higher mol wt component of normal C1-INH (106,000 mol wt) appeared to form a stable complex with the plasma kallikrein. whereas both the 106.000 and 96,000 mol wt forms made stable complexes with Cli When a preparation of normal Cl -INH containing a homogeneous single band of C1-INH was exposed to C1 or kallikrein, a “dou-