Schematic representation of recombinant constructs. (A) Simplified domain structure of mature fl-VWF monomer. The FVIII-binding site in the D′D3 domains is indicated above. O- and N-linked glycosylation is indicated by open and full circles, respectively. (B) VWF-12 is a dimer of the D′D3 domains and 3 repeats of a 31-aa fragment downstream of D3 that is rich in O-linked glycosylation sites. (C) VWF-13 dimer contains the D′D3 and A1-A2-A3 domains of VWF. CTCK, C-terminal cystine knot.