Protein engineering of ribonucleases

Natural bovine seminal RNase possesses a potent antitumor action. We have m utagenized monomeric bovine pancreatic RNase A, devoid of any cytotoxic act ion, to insert residues present at corresponding positions in the subunit o f dimeric, antitumor, seminal RNase. Like naturally dimeric seminal RNase, the mutant dimeric RNases display selective toxicity for malignant cells, w hich is absent in the monomeric mutants. (C) Societe francaise de biochimie et biologie moleculaire / Elsevier, Paris.