site map  

β -Thrombin, γ -Thrombin

Human Proteins   Bovine Proteins   Mouse Proteins   Other Species  Inhibitors

   Substrates   Antibodies   Sample Collection Tubes  Assay Kits  Deficient Plasmas  Pricing

Haematologic Technologies, Inc.

57 River Road

Essex Junction, VT USA

Tel: 802.878.1777

Fax: 802.878.1776

Email: hti@haemtech.com

HOME PAGE

PROTEOLYZED FORMS OF α-THROMBIN The degradation of α-thrombin to less active forms, either by autoproteolysis or limited trypsin digestion, is illustrated above. β-thrombin is generated by cleavage at Arg-70/73 in the thrombin B-chain, giving rise to the B1 and B2 peptides. γ-thrombin is generated from β-thrombin by the additional cleavage at Arg-154 of the B-chain, giving rise to the B4 and B5 peptides from the B2 peptide.

Alpha-thrombin is a highly specific serine protease generated by proteolytic activation of the zymogen prothrombin (1). Purified forms of α-thrombin have been shown (2-4) to undergo autolysis upon long term storage to less active forms. Similar inactivation was observed upon limited digestion of a-thrombin with trypsin (5). These proteolyzed forms of α-thrombin have been termed β-thrombin and γ-thrombin. β-thrombin is produced by the cleavage of the Arg-70 or the Arg-73 bond in the thrombin B-chain. Another form of proteolyzed thrombin, termed β'-thrombin is formed by the single cleavage of thrombin at Arg-154. γ-thrombin is produced by proteolytic cleavage at both of these sites (Arg70/73 and Arg-154) in the B-chain. These cleavages cause release of peptides that are no longer covalently attached to the thrombin molecule, but remain associated through ion exchange and gel filtration chromatography. These proteolyzed forms of thrombin retain their ability to cleave small synthetic substrates (6,7) and some protein substrates such as factor XIII (8), antithrombin III (9) and prothrombin (10). Their ability to clot fibrinogen (11), cleave thrombospondin (12) or activate protein C (9) have been markedly decreased. 

Human β-thrombin and γ-thrombin are prepared from purified a-thrombin by limited proteolysis with TPCK-treated trypsin, essentially by the method of Braun et al. (5). The proteolyzed forms of a-thrombin are supplied in 100 mM NaH2PO4, pH 6.5 buffer and should be stored at -20ºC. Purity is assessed by SDS-PAGE and activity is assessed using a fibrinogen clotting assay. 

Properties of β and γ-Thrombin

PRICING

INQUIRE ABOUT THIS PRODUCT

References 

1. Lundblad, R.L., et al., Methods Enzymol., 45, 156 (1976). 
2. Lundblad, R.L., et al., J. Biol. Chem., 254, 8524 (1979). 
3. Fenton, J.W., et al., in Chemistry and Biology of Thrombin, ed. R.L. Lundblad, J.W. Fenton, K.G. Mann, pp. 43-70, Ann Arbor, MI: Ann Arbor Science Publishers, Inc., 1977. 
4. Boissel, J.P., et al., J. Biol. Chem., 259, 5691 (1984). 
5. Braun, P.J., et al., Thromb. Res., 50, 273 (1988). 
6. Lottenberg, R., et al., Thromb. Res., 28, 313 (1982). 
7. WittiNg, et al., Thromb. Res., 46, 567 (1987). 
8. Lorand, L. and Credo, R.B., in Chemistry and Biology of Thrombin, ed. R.L. Lundblad, J.W. Fenton, K.G. Mann, pp. 311-323, Ann Arbor, MI: Ann Arbor Science Publishers, Inc., 1977. 
9. Bezeaud, A., et al., Eur. J. Chem., 153, 491 (1985). 
10. Seegers, W.H., et al., Semin. Thromb. Haemostasis, 1, 211 (1975). 
11. Lundblad, R.L., et al., J. Biol. Chem., 259, 6991 (1984). 
12. Takahashi, K., et al., Biochem. J., 224, 673 (1984).

 Please inquire about products not listed.  We can also custom purify proteins from other species.