Fig. 3.

Activity of recombinant G. lamblia nitroreductases GlNR1 (NR1) and GlNR2 (NR2) with 7-nitrocoumarine as a substrate (0.1 mM) and with NADH as an electron donor. The reaction was performed at 37 °C with GlNR1, GlNR2 alone (125 ng each) or together (62.5 ng each) and stopped after various time points by addition of one volume HCl 0.05 M. Formation of 7-aminocoumarin was quantified by fluorimetry (excitation at 365 nm, emission at 455 nm). Mean values (±SE) are given for three replicates. Values marked by asterisks are significantly different from each other (paired t-test, two-sided, *p < 0.01).