Ein Beitrag zur Isolierung und Charakterisierung des C‐Inaktivators aus Humanplasma

Abstract

A simple procedure for the isolation of C‐Inactivator from fresh human ACD plasma is described consisting of the following fractionation steps: DEAE chromatography, ammonium sulfate precipitation, Sephadex G‐150 gel filtration and zone electrophoresis. A 250‐fold concentration was achieved in good agreement with an immunologically determined C‐Inactivator concentration of 25 mg/100 ml serum. C‐Inactivator is a glycoprotein containing 35% carbohydrates; it migrates with the α 2 ‐globulins at pH 8.6 and in the PS‐1 zone at pH 4.4. The isoelectric point is between 2.7–2.8. It had s 20, w of 3.67 and a molecular weight of 104000 according sedimentation equilibrium patterns. C‐Inactivator could not be dissoziated in subunits even not by reduction with 2‐mercaptoethanol and subsequent alkylation with iodoacetamide. 1 mg C‐Inactivator neutralizes 17 C‐Inactivator units respectively 5 Remmert and Cohen plasmin units. Only weak affinities for trypsin and chymotrypsin were found.