Substrate specificity of Escherichia coli thymidine phosphorylase
Substrate specificity of Escherichia coli thymidine phosphorylase to thymidine derivatives modified at 5′-, 3′-, and 2′,3′- positions of the sugar moiety was studied. Equilibrium and kinetic constants (Km, KI, kcat) of the phosphorolysis reaction have been determined for 20 thymidine analogs. The results are compared with X-ray and molecular dynamics data. The most important hydrogen bonds in the enzyme-substrate complex are revealed. © Nauka/Interperiodica 2007.