Wp. Mielicki et Sg. Gordon, 3-STAGE CHROMOGENIC ASSAY FOR THE ANALYSIS OF ACTIVATION PROPERTIES OF FACTOR-X BY CANCER PROCOAGULANT, Blood coagulation & fibrinolysis, 4(3), 1993, pp. 441-446
The cysteine proteinase, cancer procoagulant (CP; EC 3.4.22.26) was is
olated from human amnion-chorion and purified by precipitation with po
lyethylene glycol and either ion exchange or immunoaffinity chromatogr
aphy. A new, sensitive, three-stage chromogenic assay was developed fo
r determination of CP factor X-activating activity. Using this assay s
ome properties including dose-response, effect of calcium, phospholipi
d and pH on the activation of factor X by CP were determined. There wa
s an excellent linear correlation (r2 = 0.99) between concentration an
d the enzymatic activity of CP. The activation of factor X by purified
CP was calcium dependent with an optimum calcium concentration of 7 m
M. CP was not phospholipid dependent. There was a rather broad pH opti
mum between pH 6.9 and 7.25 for the activation of factor X by CP.