Crystal structure and substrate-induced activation of ADAMTS13

Abstract

Platelet recruitment to sites of blood vessel damage is highly dependent upon von Willebrand factor (VWF). VWF platelet-tethering function is proteolytically regulated by the metalloprotease ADAMTS13. Proteolysis depends upon shear-induced conformational changes in VWF that reveal the A2 domain cleavage site. Multiple ADAMTS13 exosite interactions are involved in recognition of the unfolded A2 domain. Here we report through kinetic analyses that, in binding VWF, the ADAMTS13 cysteine-rich and spacer domain exosites bring enzyme and substrate into proximity. Thereafter, binding of the ADAMTS13 disintegrin-like domain exosite to VWF allosterically activates the adjacent metalloprotease domain to facilitate proteolysis. The crystal structure of the ADAMTS13 metalloprotease to spacer domains reveals that the metalloprotease domain exhibits a latent conformation in which the active-site cleft is occluded supporting the requirement for an allosteric change to enable accommodation of the substrate. Our data demonstrate that VWF functions as both the activating cofactor and substrate for ADAMTS13.

Insights Into Immunothrombosis: The Interplay Among Neutrophil Extracellular Trap, von Willebrand Factor, and ADAMTS13

“…Notably, the lack of spacer domain results in a dramatic reduction in its proteolytic activity, suggesting spacer domain is vital (75,76). Although the crystal structure of full length ADAMS13 is not available to date, the crystal structure of its MDTCS provides critical insights into ADAMTS13 binding and cleavage (77,78). Akiyama et al firstly crystallized the DTCS structure in 2009 (79).…”

“…Recently, Petri et al crystallized a Fab-MDTCS structure. The authors proposed that the M domain exhibited a latent conformation, and the binding of exosite-1 to VWF allosterically activated the M domain to facilitate proteolysis (77).…”

International Council for Standardization in Haematology (ICSH) recommendations for laboratory measurement of ADAMTS13

“…The other domains of ADAMTS13 play a role in the attachment and unravelling of VWF, while VWF itself induces conformational changes in ADAMTS13, making it fully active. [3][4][5][6][7] Thrombotic microangiopathies (TMA) are a group of disorders characterized by thrombocytopenia and microangiopathic haemolytic anaemia (MAHA) resulting in varying degrees of organ damage; they are rare, but potentially life-threatening unless they are recognized and treated rapidly. They include thrombotic thrombocytopenic purpura (TTP) and haemolytic uraemic syndrome (HUS), 8,9 but may also be secondary to cancer, viral infection (eg HIV), organ or bone marrow transplantation, pregnancy (preeclampsia/eclampsia or HELLP syndrome), severe hypertension, drugs, autoimmune disorders, sepsis and disseminated intravascular coagulation.…”

ADAMTS Proteases: Potential Biomarkers and Novel Therapeutic Targets for Cartilage Health

“…Additionally, they lack catalytic activity due to the absence of prometalloprotease and the disintegrin-like domain which are found in the ADAMTSs [21][22][23][24]. ADAMTSs differ from ADAMs with the lack of a transmembrane domain and the inclusion of well-conserved thrombospondin 1-like repeats, a cysteine-rich domain, and the CUB (complement subcomponents C1s/ C1r, Uegf, BMP1) domain, thus being soluble extracellular proteases [25][26][27][28][29][30][31].…”