TY - JOUR
T1 - Oxidized von Willebrand factor is efficiently cleaved by serine proteases from primary granules of leukocytes: divergence from adamts-13
AU - Lancellotti, Stefano
AU - Rutella, Sergio
AU - De Cristofaro, Raimondo
PY - 2011
Y1 - 2011
N2 - Background: The leukocyte serine proteases (LSPs) elastase, proteinase 3 and cathepsin G cleave von Willebrand factor (VWF) near or at the same cleavage site (Tyr1605-Met1606) as ADAMTS-13, the metalloprotease that specifically controls the proteolytic processing of VWF. Recent studies showed that oxidation of VWF at Met1606 with formation of sulfoxy-Met (MetSO) severely impairs its proteolysis by ADAMTS-13. Design and Methods: This study was aimed at assessing whether or not oxidation of VWF by reactive oxygen species (ROS) may also affect its cleavage by elastase, proteinase 3 and cathepsin G. In this study the catalytic specificity of hydrolysis by LSPs of the VWF peptide substrate VWF74 and full length VWF, both in unaltered or oxidized form was measured by RP-HPLC, electrophoretic and mass spectrometry methods. Results: LSPs cleave both VWF multimers and VWF74 near or at the same peptide bond hydrolyzed by ADAMTS-13 with k(cat) /K(m) values similar to that of the metalloprotease. However, at variance with ADAMTS-13, cathepsin G cleaved VWF74 containing a MetSO residue at position 1606 with a k(cat) /K(m) value higher than VWF74, whereas the catalytic efficiency of both elastase and proteinase 3 was unaffected by the substitution of Met1606 with MetSO. Likewise, oxidation of VWF multimers by HClO and ROS, produced by activated leukocytes, improved their hydrolysis by LSPs. Conclusions: Oxidation by leukocyte ROS has a net positive effect on cleavage of VWF multimers by LSPs, under conditions where high concentrations of oxidant species would severely reduce the proteolytic efficiency of ADAMTS-13.
AB - Background: The leukocyte serine proteases (LSPs) elastase, proteinase 3 and cathepsin G cleave von Willebrand factor (VWF) near or at the same cleavage site (Tyr1605-Met1606) as ADAMTS-13, the metalloprotease that specifically controls the proteolytic processing of VWF. Recent studies showed that oxidation of VWF at Met1606 with formation of sulfoxy-Met (MetSO) severely impairs its proteolysis by ADAMTS-13. Design and Methods: This study was aimed at assessing whether or not oxidation of VWF by reactive oxygen species (ROS) may also affect its cleavage by elastase, proteinase 3 and cathepsin G. In this study the catalytic specificity of hydrolysis by LSPs of the VWF peptide substrate VWF74 and full length VWF, both in unaltered or oxidized form was measured by RP-HPLC, electrophoretic and mass spectrometry methods. Results: LSPs cleave both VWF multimers and VWF74 near or at the same peptide bond hydrolyzed by ADAMTS-13 with k(cat) /K(m) values similar to that of the metalloprotease. However, at variance with ADAMTS-13, cathepsin G cleaved VWF74 containing a MetSO residue at position 1606 with a k(cat) /K(m) value higher than VWF74, whereas the catalytic efficiency of both elastase and proteinase 3 was unaffected by the substitution of Met1606 with MetSO. Likewise, oxidation of VWF multimers by HClO and ROS, produced by activated leukocytes, improved their hydrolysis by LSPs. Conclusions: Oxidation by leukocyte ROS has a net positive effect on cleavage of VWF multimers by LSPs, under conditions where high concentrations of oxidant species would severely reduce the proteolytic efficiency of ADAMTS-13.
KW - Leukocyte serine proteases
KW - Oxidative stress
KW - VWF
KW - Leukocyte serine proteases
KW - Oxidative stress
KW - VWF
UR - http://hdl.handle.net/10807/32881
M3 - Article
SN - 1538-7933
VL - 2011
SP - 1620
EP - 1627
JO - Journal of Thrombosis and Haemostasis
JF - Journal of Thrombosis and Haemostasis
ER -