Expression of Bovine Seminal Ribonuclease in Escherichia coli

Bovine seminal RNase, an unusual member of the pancreatic-like ribonuclease superfamily, is also a multifunctional biological effector with antitumor, immunosuppressive and antispermatogenic activities. We report the cloning of a semi-synthetic cDNA coding for the protein subunit chain, its expression with a T7 expression system in E. coli, the dimerization of correctly reoxidized monomeric protein followed by the purification of the recombinant enzyme in high yields. The recombinant protein is undistinguishable from BS-RNase as purified from seminal vescicles both in its catalytic activity and in its quaternary structure micro-heterogeneity