Static collagen-binding assay. The ability of mutant recombinant mVWFs to bind collagen type I or III was determined by ELISA and normalized to wild-type VWF. p.L1757A showed significant enhanced binding. p.S1731T showed distinct responses to collagen type I or III. The other mutations showed significant decreased binding (n = 8). *P < .05, **P < .01, ***P < .001.