RECOMBINANT ONCONASE, AND CHEMICAL CONJUGATES AND FUSION PROTEINS OF RECOMBINANT ONCONASE

摘要

Recombinantly-produced Onconase molecules and fusion proteins containing the same are disclosed. The recombinantly-produced Onconase molecule has the sequence of native Onconase, retains the proper folding of native Onconase and has cytotoxic activity similar to that of Onconase purified from oocytes of Rana pipiens. cDNA coding for Onconase is extended by one triplet which codes for N-formyl-methionine. When expressed recombinantly, the mutant Onconase has N-formyl-methionine as the N-terminal amino acid, and glutaminyl as the penultimate N-terminal residue. Following expression, the N-formyl methionine residue is cleaved and the penultimate glutaminyl residues are cyclized to produce Onconase with an N-terminal pyroglutamate residue, and hence the same structure and function as native Onconase.