Abstract

In order to express recombinant porcine TGF-β1 protein in a baculovirus expression system the entire TGF-β1 gene containing extra amino acids at the N terminus was cloned into pFBa and pFBb of the Bac-To-Bac^TM baculovirus expression system. One of the clones contained 106 extra amino acids and was designated pFBa-106 TGF-β1, and the other had 28 extra amino acids and was designated pFBb-28 TGF-β1. The orientation of the gene was identified with restriction enzyme mapping and PCR with internal TGF-β1 primers. Sf-9 cells were infected at a m.o.i. of 10 by the recombinant viruses generated from the two expected sizes of 55 kD and 46.4kD. these precursor forms of TGF-β1 with a polyclonal antibody against human TGF-β1. No mature form of TGF-β1 protein was detected on SDS gels and an immunoblot indicated that TGF-β1 precursor is not properlu processed in insect cells.

• Keywords: TGF-β1; baculovirus expression; recombinant protein; precursor