Substrate Specificity of Purine Nucleoside Phosphorylase E. coli in Phosphorolysis Reactions of Purine Ribonucleotides Containing a Cyclic Terpene Fragment

Bacterial purine nucleoside phosphorylase (PNP) E. coli can be considered as an attractive model enzyme for investigation of metabolism and stability of biologically active nucleosides in a cell. This work is devoted to the investigation of the substrate specificity of E. coli PNP in the reactions of phosphorolytic cleavage of the glycoside bond in adenosine derivatives containing a cyclic terpene fragment as precursors for the production of biologically active purine derivatives. A number of N-terpene substituted adenosine derivatives with different structures of the hydrocarbon substituent were obtained. By measuring the kinetic parameters of the phosphorolysis reaction, it was shown that adenosine derivatives containing a bicyclic hydrocarbon fragment bind to the enzyme more efficiently than a monocyclic derivative. The obtained results make it possible to produce new purine derivatives containing a lipophilic terpene fragment under mild reaction conditions.