Structure-function study of recombinant onconase variants

A method for expression of an onconase gene leading to a soluble form of th e protein was developed. The enzymatic and cytotoxic properties of the prot ein's recombinant forms were studied. Recombinant onconase with an addition al N-terminal Met residue isolated in non-denaturing conditions did not sub stantially differ from the native enzyme in ribonucleolytic activity. The a ddition of a 33-mer peptide containing auxiliary elements for the simplific ation of isolation and detection of the recombinant protein did not affect the enzyme properties of onconase. The method proposed is useful for the on conase structure-function relation studies and enables construction of onco nase-based fusion proteins for anticancer therapy.