Exosite interactions contribute to tension-induced cleavage of von Willebrand factor by the antithrombotic ADAMTS13 metalloprotease
| Autor: | Elodee A. Tuley, Patricia J. Anderson, Elaine M. Majerus, Weiqiang Gao, J. Evan Sadler |
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| Rok vydání: | 2006 |
| Předmět: |
Von Willebrand factor type A domain
Plasma protein binding Cleavage (embryo) Cell Line Substrate Specificity Scissile bond Von Willebrand factor hemic and lymphatic diseases von Willebrand Factor Disintegrin Humans Multidisciplinary biology Chemistry C-terminus Genetic Variation Metalloendopeptidases Thrombosis Biological Sciences Recombinant Proteins ADAMTS13 Kinetics Biochemistry biology.protein Biophysics Protein Binding |
| Zdroj: | Proceedings of the National Academy of Sciences. 103:19099-19104 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.0607264104 |
| Popis: | Von Willebrand factor (VWF) is a multimeric protein that mediates platelet adhesion at sites of vascular injury, and ADAMTS13 (a disintegrin and metalloprotease with thrombospondin)is a multidomain metalloprotease that limits platelet adhesion by a feedback mechanism in which fluid shear stress induces proteolysis of VWF and prevents disseminated microvascular thrombosis. Cleavage of the Tyr 1605 –Met 1606 scissile bond in the VWF A2 domain depends on a Glu 1660 –Arg 1668 segment in the same domain and on the noncatalytic spacer domain of ADAMTS13, suggesting that extensive enzyme–substrate interactions facilitate substrate recognition. Based on mutagenesis and kinetic analysis, we find that the ADAMTS13 spacer domain binds to an exosite near the C terminus of the VWF A2 domain. Deleting the spacer domain from ADAMTS13 or deleting the exosite from the VWF substrate reduced the rate of cleavage ≈20-fold. A cleavage product containing the exosite was a hyperbolic mixed-type inhibitor of ADAMTS13 proteolysis of either VWF multimers or model peptide substrates but only if the ADAMTS13 enzyme contained the spacer domain. The specificity of this unique mechanism depends on tension-induced unfolding of the VWF A2 domain, which exposes the scissile bond and exosite for interaction with complementary sites on ADAMTS13. |
| Databáze: | OpenAIRE |
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