Purification and characterization of a cytochrome P-450 from insecticide susceptible and resistant strains of housefly, Musca domestica L., before and after phenobarbital exposure.
A cytochrome P-450 (P-450) was purified from abdominal microsomes of untreated and phenobarbital treated susceptible (S+) and insecticide-resistant (LPR) houseflies using HPLC purification procedures. The purified P-450s exhibited the same apparent molecular masses (54,400 dalton) and could not be distinguished from each other on the basis of HPLC chromatographic properties, reduced CO-difference absorbance maxima (447 +/- 0.5 nm), or partial NH2-terminal sequences (MLLLLLLIVVTTLYIFAKL). Since these P-450s were indistinguishable and were immunologically identical to cytochrome P-450lpr we conclude that these P-450s are in fact cytochrome P-450lpr. The level of P-450lpr was increased twofold after PB exposure in the S+ strain, while the level of P-450lpr did not change in the LPR strain. Immunoinhibition of ECOD activity with anti-P-450lpr antiserum suggests that PB treatment in S+ house flies induced P-450lpr, and other forms of cytochromes P-450 with high activity toward this substrate.
Department of Entomology, Cornell University, Ithaca, New York 14853-0999.
J G
JG
Scott
S S
SS
Lee
D000595:Amino Acid Sequence; D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D004351:Drug Resistance; D005260:Female; D006793:Houseflies / Q000201:enzymology* / Q000235:genetics; D007120:Immunochemistry; D007306:Insecticides / Q000494:pharmacology; D008861:Microsomes / Q000201:enzymology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010634:Phenobarbital / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid
D007306:Insecticides; D003577:Cytochrome P-450 Enzyme System; D010634:Phenobarbital