[Hexamere purine nucleoside phosphorylase from Escherichia coli K-12. Kinetic analysis and mechanism of reaction].

A kinetic analysis of the phosphorolytic reaction catalyzed by hexameric purine nucleoside phosphorylase II from E. coli K-12 in the presence and absence of reaction products was carried out. The results of the kinetic analysis are consistent with a rapid equilibrium random Bi-Bi mechanism, in which a dead-end ternary (enzyme.purine base.phosphate) complex is formed.