BACULOVIRUS-MEDIATED EXPRESSION OF CHICKEN GROWTH-HORMONE

A full-length chicken growth hormone (cGH) cDNA was placed downstream from the Autograph californica nuclear polyhedron virus, AcNPV, polyhe dron gene promoter and expressed in Sf9 insect cells. Secreted recombi nant cGH levels averaged 2-10 mu g/ml from day 5-10 postinfection. The recombinant cGH analyzed by SDS-PAGE gels and Western blotting consis ted of a doublet with M-r of 26.5 and 23.5 kDa. Analysis by 2-D electr ophoresis of partially-purified recombinant cGH and purified native cG H revealed similar immunoreactive charge isoforms and M-r variants. Th e recombinant hormone was biologically active in a homologous radiorec eptor assay. The results show that cGH expressed in insect cells is bi ologically and immunologically active, and that a variety of isoforms are secreted which exhibit size and charge properties similar to those of pituitary-derived cGH. (C) 1997 Elsevier Science Inc.