Antigen levels, half-life, multimeric pattern, and platelet counts of mice expressing murine VWF mutants. (A) Plasma samples were taken at 3, 7, and 14 days after injection. VWF antigen levels are expressed as the percentage of normal mouse plasma (NMP). (B) After injection with NHS–biotin, residual biotinylated VWF was determined at indicated time points. Data present the percentage of residual biotinylated VWF measured at t = 0, which was set at 100% for each mouse. Curves indicate the best fit of a single exponential decay. Data over 6 hours are shown. For calculation of half-life, data over a 24-hour period were used. (C) Multimer composition of circulating VWF proteins. (Lane 1) Wt-mVWF; (lane 2) mVWF/R11306Q with full multimer range; (lane 3) mVWF/R1306Q with loss of high multimers; (lane 4) mVWF/V1316M with full multimer range; (lane 5) mVWF/V1316M with loss of high multimers. No difference in multimeric composition was observed between samples taken at day 3 and day 7. (D) Platelet counts at days 3, 7, and 14. (A-C) ● indicates wt-mVWF; □, mVWF/R1306Q; ○, mVWF/V1316M. Data represent mean ± SE. (A,D) n = 6 for wt-mVWF and n = 5 for each mutant. (B) n = 3 for each time point. Data at day 0 (A,D) represent analysis of samples taken 4 days before hydrodynamic injection.