Prekallikrein Deficient Plasma

Affinity’s Prekallikrein Deficient Plasma is manufactured from pooled normal human plasma depleted of Prekallikrein using antibodies directed to PK. 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 Prekallikrein Deficient or Depleted Plasma from Affinity Biologicals are for Research Use Only and must not be used for diagnostic applications.

Prekallikrein Deficient – Depleted Plasma

Prekallikrein Deficient – Depleted Plasma is manufactured from normal citrated human plasma that has been depleted of Prekallikrein Deficient – Depleted Plasma by selective affinity immuno-adsorption using antibodies directed towards PK. 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 Prekallikrein Deficient – Depleted Plasma can be used for further manufacturing or research use only applications.

Frozen Prekallikrein Deficient Plasma

Product Code: PK-DP

Presentation: Frozen Prekallikrein Deficient – Depleted Plasma

Preparation/Handling: Thaw 1 ml vials in 37^oC 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 -60^oC. Product is stable until date stated on vial label when stored at -60^oC. Once thawed, plasma is stable for 4 hours at 2-8^oC in original vial.

Certificate of Analysis: available upon request

Lyophilized Prekallikrein Deficient Plasma

Product Code: PK-LDP

Presentation: Freeze Dried Prekallikrein 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 (18-25^oC), or 30 days at –20^oC.

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 2-8^oC. Stability after reconstitution is 4 hours at ambient (18-25^oC), or 30 days at –20^oC.

Certificate of Analysis: available upon request

Description of Prekallikrein (PK)

Prekallikrein (PK), previously known as Fletcher Factor, is a single chain glycoprotein produced in the liver. The plasma concentration of PK is 50 μg/ml (550 nM), approximately 75% of which circulates in complex with high molecular weight kininogen (HK) and the remainder as free PK. Plasma PK is heterogeneous in both mass and charge due to variable degrees of glycosylation. Approximately 90% of plasma PK has an apparent molecular weight of 88 kDa as determined by SDS-PAGE and the remaining 10% has an apparent mass of 85 kDa. The catalytic site resides in the light chain. The heavy chain of PK contains four apple-domain structures similar to those found in FXI and these are required for binding of PK to HK. PK is the zymogen form of the enzyme kallikrein, which is involved in the proteolysis of kininogens with subsequent release of bradykinin, a potent vasodilator. PK participates in the contact phase of coagulation as a substrate for surface-bound activated factor XII (FXIIa) in the presence of the cofactor HK. As PK and factor XI (FXI) both circulate in complex with HK, both are localized to activating surfaces through their respective binding to HK. Limited proteolysis of PK by FXIIa generates kallikrein, a two-chain serine protease that initiates the reciprocal activation of PK and FXI. Kallikrein activity in plasma is regulated predominantly by C1-Inhibitor and α2macroglobulin, with relatively minor contributions by Protein C Inhibitor, α2antiplasmin, and antithrombin^1-3.

References and Reviews

Coleman RW, Schmaier AH; Contact System: A Vascular Biology Modulator With Anticoagulant, Profibrinolytic, Antiadhesive and Proinflammatory Attributes. Blood 90, pp 3819-3843, 1997.
DeLa Cadena R, Watchtfogel YT, Colman RW, in Hemostasis and Thrombosis, 3rd Edition, eds. RW Colman, J Hirsh, VJ Marder and EW Salzman, pp. 219-240, J.B. Lippincott Co., Philadelphia, 1994.
Hojima Y, Pierce JV, Pisano JJ; Purification and Characterization of Multiple Forms of Human Plasma Prekallikrein. JBC 260, pp 400-406, 1985.

Related Products: