Protein S Deficient Plasma
Affinity’s Protein S Deficient Plasma is manufactured from pooled normal human plasma depleted of Protein S using antibodies directed to PS. Only the highest quality citrated plasma is used as starting material. Our Frozen Deficient or Depleted Plasma products are typically buffered with the addition of HEPES to 20mM final concentration and our Lyophilized Deficient Plasma products are typically buffered with the addition of HEPES to 50mM final concentration.
All Protein S Deficient or Depleted Plasma from Affinity Biologicals are for Research Use Only and must not be used for diagnostic applications.
Protein S Deficient – Depleted Plasma
Protein S Deficient – Depleted Plasma is manufactured from normal citrated human plasma that has been depleted of Protein S by selective affinity immuno-adsorption using antibodies directed towards Protein S. Available in two different formats – Frozen and Lyophilized
Only the highest quality citrated plasma is used as starting material and in many cases the parent plasma is available as control material. Our Protein S Deficient – Depleted Plasma can be used for further manufacturing or research use only applications.
Frozen Protein S Deficient Plasma
Product Code: PS-DP
Presentation: Frozen Protein S Deficient – Depleted Plasma
Preparation/Handling: Thaw 1 ml vials in 37oC water bath for 5 minutes; for bulk volumes, thawing time will be dependent on bottle size.
Storage and Stability: Plasma is shipped frozen and should be stored below -60oC. Product is stable until date stated on vial label when stored at -60oC. Once thawed, plasma is stable for 4 hours at 2-8oC in original vial.
Certificate of Analysis: available upon request
Lyophilized Protein S Deficient Plasma
Product Code: PS-LDP
Presentation: Freeze Dried Protein Deficient – Depleted Plasma containing 50 mM HEPES and stabilizers.
Reconstitution: Reconstitute with 1 mL of reagent grade water. Allow contents to dissolve for 15 minutes at room temperature with occasional swirling. Stability after reconstitution is 4 hours at ambient (18-25oC), or 30 days at –20oC.
Storage and Stability: Prior to reconstitution, dried plasma should be stored at 2-8°C. Product is stable until date stated on vial label when stored at 2-8oC. Stability after reconstitution is 4 hours at ambient (18-25oC), or 30 days at –20oC.
Certificate of Analysis: available upon request
Description of Protein S (PS)
Protein S (PS) is a vitamin K-dependent glycoprotein produced in the liver, endothelium and megakaryocytes. The concentration of PS in plasma is ~25 μg/ml (~325 nM) where it acts as a cofactor in the anticoagulant activity of activated Protein C. A deficiency of Protein S (quantitative or qualitative) is a risk factor for vascular thrombosis. Protein S is expressed as a single chain molecule with a molecular weight of 77 kDa. The structure of PS is similar to many other vitamin-K dependent coagulation proteins, consisting of an N-terminal calcium binding domain of 10 γ-carboxyglutamic acid (gla) residues, followed by a thrombin-sensitive loop region and 4 EGF-like domains. The C-terminal domain does not contain the usual catalytic triad of a proenzyme, but seems instead to be involved in the binding of PS to C4b-binding protein (C4bp). Protein S binds to activated Protein C (APC) in the presence of calcium and negatively charged phospholipid surface to allow APC to proteolytically inactivate coagulation cofactors Va and VIIIa. Enzymatic regulation of PS cofactor activity is through cleavage of PS in the thrombin-sensitive loop region by thrombin or other enzymes, resulting in the loss of calcium binding properties and APC cofactor activity. Another regulatory mechanism is to reduce the availability of PS by the binding of PS to C4bp. In plasma, approximately 60% of Protein S circulates in non-covalent complex with C4bp, making it unavailable for APC cofactor activity. The binding of PS to C4bp may be important in localizing C4bp to damaged cell membranes where it may control activation of complement by the classical pathway1-3.
References and Reviews
- Broze GJ, Miletich JP; Biochemistry and Physiology of Protein C, Protein S and Thrombomodulin; in Hemostasis and Thrombosis, 3rd Edition, eds. RW Colman, J Hirsh, VJ Marder and EW Salzman, pp 259-276, J.B. Lippincott Co., Philadelphia PA, USA, 1994.
- Comp PC, Doray D, Patton D, Esmon CT; An Abnormal Plasma Distribution of Protein S Occurs in Functional Protein S Deficiency. Blood 67, pp 504-508, 1986.
- Schwalbe RA, Dahlback B, Nelsestuen GL; Independent Association of Serum Amyloid P Component, Protein S and Complement C4b with C4b-binding Protein and Subsequent Association of the Complex with Membranes; JBC 265, pp 21749-21757, 1990.
SAPS-HRP – Sheep anti human Protein S, peroxidase conjugated IgG (0.2 mg vial)
SAPS-IG – Sheep anti human Protein S, purified IgG (10mg vial)
GAPS-IG – Goat anti human Protein S, purified IgG (5mg vial)
GAPS-HRP – Goat anti human Protein S, peroxidase conjugated IgG (0.2 mg vial)
PS-EIA – Protein S Paired Antibody Set – 5 plate set
PS-DP – Frozen Protein SDeficient Plasma – 1ml or bulk quantities
PS-LDP – Lyophilized Protein S Deficient Plasma – 1ml
SAPS-AP – Sheep anti human Protein S, affinity purified IgG (0.5 mg vial)