(I) The initial selection of a particular kinetic model was based on visual inspection of the corresponding double-reciprocal plot. When this preliminary analysis did not lead to a clear model discrimination, data were fitted to both alternative velocity equations.
Caption: Figure 3: Double-reciprocal plot of the initial velocity data.
When GSSG was replaced with DTNB, an artificial substrate indicative of TR activity, identical parallel double-reciprocal plots were obtained (data not shown).
The type of inhibition for the inhibitors was determined by double-reciprocal plot and its replot of slope versus the reciprocal of the substrate concentration.
The double-reciprocal plots of norathyriol (Figure 4) revealed that the reaction followed a typical noncompetitive inhibition pattern, suggesting that norathyriol is a noncompetitive [alpha]-glucosidase inhibitor.
We thus see that the reciprocal of the intercept of a plot of the change in absorbance as a function of the reciprocal of the time (i.e., a so-called "double-reciprocal plot") yields [A.sub.0], the absorbance of the nonirradiated specimen.
The absorbance attributable to bilirubin is determined from a double-reciprocal plot of the change with time of the absorbance at 464 run between irradiated and nonirradiated specimens.
We analyzed the results graphically using the double-reciprocal plot (Lineweaver-Burke plot).
To compare the results from the enzyme saturation assays, we linearized the data in Lineweaver-Burke double-reciprocal plots, and applied the linear analysis of regression.
Caption: Figure 3: (a) Enzymatic reaction rate as a function of CA concentration for different mercury(II) concentrations; (b) double-reciprocal plot (1/V versus 1/[CA]) for the system TvL-CA inhibited for different Hg (II) concentrations; (c) inhibition percent plot of the system TvL-CA at 200 [micro]M of CA and 2-minute incubation.
The analyses of the Lineweaver-Burk double-reciprocal plots indicate that the mercury inhibition mechanism by TvL is carried out through a mix of the previous models (mixture of the competitive and noncompetitive).
The double-reciprocal plots
of 1/([A.sub.0] - A) versus 1/[c.sub.DNA] were linear at 298.15K and 308.15K, respectively.