Table 1.
Quantitative analysis of scissile bond cleavage by ADAMTS13 for WT VWF and its variants
| VWF115 | kcat/Km (×105 M−1s−1) | Fold reduction |
| WT | 9.3 ± 2.3 | — |
| DREQ/SSSS | 6.4 ± 0.7 | 1.4 |
| N1602A | 4.3 ± 0.4 | 2.2 |
| L1603S | <0.02 | >400 |
| L1603A | 0.1 ± 0.04 | 100 |
| V1604S | 1.8 ± 0.1 | 5.1 |
| Y1605A | 0.2 ± 0.05 | 38 |
| M1606A | * | 18 |
| D1614A | ** | 6.5 |
| Δ1660–8 | *** | 12.5–15 |
Specificity constants, kcat/Km, (±SD) were determined by HPLC quantitation of VWF115 proteolysis by ADAMTS13 (n ≥ 3). Values for VWF115 Leu1603 variants must be regarded as approximate because of very low cleavage rates. Results indicated by asterisks are from the literature: *, ref. 10; **, ref. 11; ***, refs. 9 and 13.