Figure 4

Lineweaver-Burke double reciprocal plots showing CHEC-9 inhibition of sPLA2 activity in human plasma. Plasma concentration was 20% of the reaction mixture, which also consisted of 10-pyrene at concentrations between 5–30 μM and CHEC-9 at 0, 10 and 50 nM. CHEC-9 was less effective or even exaggerated the reaction at the lower substrate concentrations causing the lines of the plot to converge with increasing values of 1/[S]. The kinetic parameters for reactions with human plasma are shown in Table 1 and are consistent with the properties of an uncompetitive inhibitor. [r², p values for linearity of reciprocal plots: 0 nM – 0.987, 0.006; 10 nM – 0.967, 0.0026; 50 nM – 0.980, 0.0012].