Functional activity of protein S determined with use of protein C activated by venom activator.
A new screening procedure, an easy and specific assay for determining functional Protein S activity, has been developed, with use of Protein C activated by venom activator (Protac). Purified Protein C (100% amidolytic activity) was activated by venom activator (6 units/mL). To a mixture of 100 microL of Protein S-deficient plasma, 20 microL of sample plasma, 100 microL of cephalin (Actin), and 20 microL of activated Protein C we added 100 microL of 25 mmol/L CaCl2 solution and measured the clotting time with a KC 10 coagulometer. The functional Protein S activity correlated well with the concentrations of Protein S antigen measured by enzyme immunoassay and the Laurell rocket technique (r = 0.810 and 0.850, respectively) in normal subjects, patients with myocardial infarction undergoing warfarin therapy, and patients with liver cirrhosis.
Kobayashi
I
I
2nd Department of Internal Medicine, Yamanashi Medical College, Japan.
Amemiya
N
N
Endo
T
T
Okuyama
K
K
Tamura
K
K
Kume
S
S
D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D007124:Immunoenzyme Techniques; D036341:Intercellular Signaling Peptides and Proteins; D008103:Liver Cirrhosis / Q000097:blood; D009203:Myocardial Infarction / Q000097:blood; D010455:Peptides; D011486:Protein C; D017293:Protein S
D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; D011486:Protein C; D017293:Protein S; C049647:snake venom protein C activator