title: Measurement of plasma prokallikrein independent of inhibitors and interfering enzymes.
abstract: A new method to determine plasmaprokallikrein independently of its inhibitors is described. By ion exchange chromatography with DEAE-A-50 Sephadex plasmaprokallikrein can be separated from its inhibitors Cl-esterase inhibitor, alpha 2-macroglobulin, alpha 1-antitrypsin (protease inhibitor) and antithrombin III as well as from other enzymes like plasmin, Hagemann factor and glandular kallikrein, which can interfere with the chromogenic substrate of the amidolytic assay (S 2302) used to determine plasmakallikrein activity. Furthermore, this method also allows the measurement of plasmaprokallikrein in heparinized plasma, since heparin was separated by this chromatography technique from plasmaprokallikrein too. The enzymatic activity of activated plasmakallikrein was not changed by the ion exchange chromatography. Normal values of the plasmaprokallikrein content in plasma were in the range of 2.57 +/- 0.12 U/ml of plasma (n:42; X +/- SEM). No influence on plasmaprokallikrein activity of age and sex was found.
mesh_terms: D004789:Enzyme Activation; D006801:Humans; D007610:Kallikreins / Q000097:blood / Q000502:physiology*; D007700:Kinetics; D011288:Prekallikrein / Q000302:isolation & purification / Q000502:physiology*
chemical_list: D011288:Prekallikrein; D007610:Kallikreins