Predicted model of the VWF A2 domain showing the location of N1515 and N1574. A model of the VWF A2 domain was prepared as previously described³²  and manipulated using Protein Explorer software (available from http://www.umass.edu/microbio/chime/pe_beta/pe/protexpl/, University of Massachusetts). The ADAMTS13 cleavage site, Y1605-M1606, is shown in the center of the domain. Both glycosylation sites, N1515 and N1574, are located on the same face of the A2 domain but on opposite sides of the ADAMTS13 cleavage site. Glycosylation sites are represented by ball structures and are not representative of the size of the glycan present at each site.