Overexpression of juvenile hormone binding protein in bacteria and Pichia pastoris.

Abstract Galleria mellonella juvenile hormone binding protein (JHBP) is a single chain glycoprotein with two disulfide bonds and a molecular mass of 25,880 Da. This report describes the expression of JHBP in bacteria and yeast cells ( Pichia pastoris ). The expression in bacteria was low and the protein was rapidly degraded upon cell lysis. The expression of His 8 -tagged rJHBP (His 8 -rJHBP) in P. pastoris was high and the non-degraded protein was purified to homogeneity with high yield in a one-step immobilized Ni ++ affinity chromatography. His 8 -rJHBP from P. pastoris contains one JH III binding site with K D of 3.7 ± 1.3 × 10 −7  M. The results suggest that P. pastoris is the preferred system for expression of His 8 -rJHBP in non-degraded fully active form.