Study on the structure-function relationship of polynucleotide phosphorylase: model of a proteolytic degraded polynucleotide phosphorylase.

It is already known that modification of E. coli polynucleotide phosphorylase by endogenous proteolysis induces drastic changes in both phosphorolysis and polymerisation reactions. The structural parameters of the proteolysed polynucleotide phosphorylase are described. The phosphorolysis of polynucleotide, which is quite progressive for the native enzyme, is shown to be only partially progressive for the degraded enzyme, owing to the loss of polymer attachment sites.