Monoclonal antibody PS7 is specific for human Protein S (PS), a vitamin K-dependent plasma glycoprotein with a molecular weight of approximately 70 kDa. In humans, PS is mainly synthesized by hepatocytes. Mature PS has a modular structure consisting of a Gla-domain containing a short aromatic stack, a region sensitive to cleavage by thrombin and factor Xa , 4 epidermal growth factor (EGF)-like domains, and a sex hormone-binding globulin-like region. The biologic function of PS thought to be of primary importance is its ability to enhance Activated Protein C-dependent proteolytic inactivation of factors Va and VIIIa, which are respectively the cofactors in the pro-thrombinase and tenase complexes of the coagulation cascade. In this way, PS plays an important role in regulating thrombin generation, and therefore controlling procoagulant activity. Crucial to the APC-dependent functions of PS is the high-affinity interaction between PS and negatively charged phospholipid surfaces, conferred by calcium-induced folding of the amino-terminal Gla-domain. Monoclonal antibody PS7 allows specific detection of cells carrying PS by flow cytometry.
Flow cytometry, Western blot
For flow cytometry and Western blotting, dilutions to be used depend on detection system applied. It is recommended that users test the reagent and determine their own optimal dilutions. The typical starting working dilution is 1:50.