Leukocyte proteases cleave von Willebrand factor at or near the ADAMTS13 cleavage site. Blood 2009 Aug 20;114(8):1666-74
Date
06/23/2009Pubmed ID
19541819Pubmed Central ID
PMC2731642DOI
10.1182/blood-2009-01-195461Scopus ID
2-s2.0-70349569566 (requires institutional sign-in at Scopus site) 97 CitationsAbstract
The function of von Willebrand factor (VWF) is regulated by proteolysis, which limits its multimeric size and ability to tether platelets. The importance of ADAMTS13 metalloprotease in VWF regulation is demonstrated by the association between severe deficiency of ADAMTS13 and thrombotic thrombocytopenic purpura (TTP). However, ADAMTS13 activity levels do not always correlate with the clinical course of TTP, suggesting that other proteases could be important in regulating VWF. We identified 4 leukocyte proteases that cleave the synthetic VWF substrate FRETS-VWF73 and multimeric VWF. Elastase and proteinase 3 (PR3) cleave multimeric VWF and FRETS-VWF73 at the V(1607)-T(1608) peptide bond; cathepsin G and matrix metalloprotease 9 cleave VWF substrates at the Y(1605)-M(1606) and M(1606)-V(1607) bonds, respectively. Isolated intact human neutrophils cleave FRETS-VWF73 at the V(1607)-T(1608) peptide bond, suggesting that elastase or PR3 expressed on leukocyte surfaces might cleave VWF. In the presence of normal or ADAMTS13-deficient plasma, cleavage of FRETS-VWF73 by resting neutrophils is abolished. However, activated neutrophils retain proteolytic activity toward FRETS-VWF73 in the presence of plasma. Although the in vivo relevance remains to be established, these studies suggest the existence of a "hot spot" of VWF proteolysis in the VWF A2 domain, and support the possibility that activated leukocytes may participate in the proteolytic regulation of VWF.
Author List
Raife TJ, Cao W, Atkinson BS, Bedell B, Montgomery RR, Lentz SR, Johnson GF, Zheng XLAuthor
Robert R. Montgomery MD Adjunct Professor in the Pediatrics department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
ADAM ProteinsADAMTS13 Protein
Amino Acid Motifs
Animals
Binding Sites
Catalytic Domain
Humans
Leukocytes
Mice
Mice, Inbred C57BL
Peptide Hydrolases
Protein Denaturation
Protein Multimerization
von Willebrand Factor