Isolation and Biochemical Characterization of a New Thrombin-Like Serine Protease from Bothrops pirajai Snake Venom

Table 1

Effect of inhibitors on enzymatic activity of SP.

Inhibitors	% inhibition of
	S-2238	S-2222	S-2303
Benzamidine	62±4	61±2	47±1
PMSF	55±3	52±3	45±3
EDTA	7.5±1	15±2	5±2
O-Phe	3.9±2	3±1	4.5±2

The inhibitors in final concentration, benzamidine (15 mM), PMSF (2 mM), EDTA (20 mM), or O-Phe (0.3 mM) were preincubated with SP (20 μg/mL) for 60 min at 37°C; then the reaction was initiated by adding chromogenic substrates (0.1 mM, final concentration). The reaction was monitored for 5 min, as described in the Section 2 and % inhibition was measured. 100% of the SP enzymatic activity was obtained in the absence of inhibitors for each substrate. Results are expressed as means ± SD of two individual experiments (𝑛=2).