The present invention relates to the production of large quantities of a novel chimeric TGF- beta , termed TGF- beta 1/ beta 2, by eucaryotic host cells transfected with recombinant DNA vectors containing the TGF- beta 1/ beta 2 precursor coding sequence controlled by expression regulatory elements. Simian TGF- beta 1 cDNA (Sharples et al., 1987, DNA 6:239-244) was modified so that the nucleotides encoding amino acid residue numbers 9-13, 17, 19, 25 and 26 of the mature TGF- beta 1 sequence were hanged to the nucleotides encoding the corresponding amino acids of the mature TGF- beta 2 structure. Simian codon usage was maintained. The chimeric TGF- beta 1/ beta 2 of the invention induces effects on the proliferation of vascular endothelial cells equivalent to those induced by TGF- beta 1. |