Expression and purification of human interleukin-1beta converting enzyme from Trichoplusia ni insect cells using a baculovirus expression system.

Employing a baculovirus expression system, human interleukin-1beta converting enzyme (ICE) has been expressed in Trichoplusia ni High-Five insect cells and purified. ICE was expressed with an N-terminal T7 epitope, thus allowing its purification using immobilized anti-T7 antibodies. The recombinant ICE was purified to >95% homogeneity, the one minor contaminant being the baculovirus anti-apoptotic protein (P35) which was copurified. The purified recombinant ICE was biologically active, cleaving both pIL-1beta and poly(ADP-ribose) polymerase substrates. The kinetic properties of the purified recombinant ICE compare favorably with native ICE purified from a THP-1 monocytic line.