Figure 7
Kinetic model of the GlcNAc 6 hydrolysis catalyzed by Vh Nag2. Mn and E represent free oligosaccharide substrate and the free enzyme, respectively. The subscripts n and i indicate the size of GlcNAc oligosaccharide. A i , B i,n-i , and C n,i represent the enzyme-substrate complexes at various stages as shown in the figure. The gray-boxes indicate the subsites possessing unfavorable positive binding free energy changes (-2 and +4 subsites). At subsite +4, the sugar residue binding is moderately unfavorable, but at subsite -2 sugar residue binding is strictly prohibited. The simultaneous differential equations were derived from the reaction model, and numerically solved to obtain the calculated time-course. The details of the calculation method are described in ref. [31].