Expression of the Mature Yellowfin Porgy Growth Hormone in Spodoptera frugiperda 21-AE Cells

A complementary DNA (564 base pairs) encoding for the mature region of the growth hormone (GH) of yellowfin porgy Acanthopagrus latus was amplified by polymerase chain reaction. This resultant DNA fragment , ypmGH cDNA, was inserted into baculovirus expression vectors, pAc7 , under the control of the polyhedrin promoter. A 22 kDa pro tein, similar to that of authentic GH , was expressed intracellularly by the insect cell line of Spodoptera frugiperda 21-AE infected by recombinant baculovirus . This protein was reactive with rabbit polyclonal antibodies raised against natural chum salmon GH . Further more, a protein band with 22 kDa labeled with [35S] methionine was detected in tha lysate of cells infected with recombinant virus containing ypmGH cDNA . Results from treatment with tunicamycin , an inhibitor of N-link glycosylation, demonstrated that the N-glycosyla tion did not occur in the recombinant GH produced by this system .