Abstract: Regional mutagenesis of a gene for angiogenin to produce DNA sequences encoding mutant proteins having increased angiogenic activity are disclosed. Expression vectors containing these sequences are introduced into host cells and direct the production of mutant angiogenic proteins with markedly increased angiogenic activity. Replacement of amino acids in a region at or corresponding to residues 8-22 of angiogenin, with other amino acids, in particular, with amino acids corresponding to residues 7-21 of RNase, unexpectedly yields a mutant angiogenin/RNase hybrid protein with 10-fold increased angiogenic potency in the chorioallantoic membrane assay. Other in vivo and in vitro angiogenin-related activities are altered in the mutant hybrid protein.

Abstract: Regional mutagenesis of a gene for angiogenin to produce DNA sequences encoding mutant proteins having increased angiogenic activity are disclosed. Expression vectors containing these sequences are introduced into host cells and direct the production of mutant angiogenic proteins with markedly increased angiogenic activity. Replacement of amino acids in a region at or corresponding to residues 8-22 of angiogenin, with other amino acids, in particular, with amino acids corresponding to residues 7-21 of RNase, unexpectedly yields a mutant angiogenin/RNase hybrid protein with 10-fold increased angiogenic potency in the chorioallantoic membrane assay. Other in vivo and in vitro angiogenin-related activities are altered in the mutant hybrid protein.