The activity of thrombin (10 pM) was measured following the hydrolysis of the fluorogenic substrate Boc-Ile-Glu-Gly-Arg-7-amido-4-methylcoumarin hydrochloride, with or without 10 minutes pre-incubation, in the presence of 100 nM NaCl and either 1 nM anophelin (a) or 1 nM cE5 (b) in the assay buffer. T, thrombin no preincubation; Tpre, thrombin with preincubation; T + I, thrombin + inhibitor no preincubation; (T + I)pre, thrombin + inhibitor with preincubation. Data represent the mean of triplicates. Error bars represent SEM. Activity of thrombin is reported as arbitrary fluorescence unit.