Figure 4

Functional comparison of P. pastoris and Sf9 insect cell expression systems. The specific activities of CHRM2 from P. pastoris and Sf9 insect cells are shown (A). CHRM2 expression was induced by the addition of methanol in P. pastoris and by the infection of baculovirus in Sf9 insect cells. The total CHRM2 protein (mg) expressed from 5 L-cultures of P. pastoris and Sf9 insect cells was assessed by a specific ligand binding assay (B). To compare the quality of CHRM2 from P. pastoris (C) and Sf9 insect cells (D), biochemical properties were evaluated by Kd and Bmax values from saturation curves and scattered plots.