Precipitation of Micorsomal Proteins in Helicoverpa armigera by PEG8000

In order to develop a protocol for purifying cytochrome P450 in the cotton bollworm, Helicoverpa armigera, the precipitation results of PEG8000 at different concentration to microsomal proteins of cotton bollworm were compared. The results showed that at the concentration of 8.0×104 mg/L, 78% microsomal proteins including 28% total P450 of midgut microsome or 34% total P450 of fatbody microsome were precipitated. SDS-PAGE showed that most of the precipitated microsomal proteins from midgut were those which molecular weight was among the range of 14.1 ~40 kD and 66 ~97 kD.