FIGURE 6.

Kinetic accounting of the action of prothrombinase on prothrombin variants. Normalized rates ± 2 S.D. for the consumption of all prothrombin variants with the exception of II_Q320 are plotted versus measured values for K_s*₃₂₀. The solid black line was calculated using Equations 1, 2, and 5 using the values in Table 2 (see “Results”), K_s*₂₇₁ = 4.3, k_cat320 = 94 s⁻¹, and k_cat271 = 100 s⁻¹. The red and blue lines denote the fractional contributions of cleavage at the 320 region or the 271 site to the rate of prothrombin cleavage.