Abstract
1. A new microsomal preparation, obtained from whole houseflies is described in terms of its cytochrome P-450 content and its hydroxylating activity. 2. Microsomes prepared from whole-fly brei, obtained with the aid of a mortar (a procedure that avoids the destruction of sarcosomes), contain 0.265nmol of cytochrome P-450 and hydroxylate naphthalene at a rate of 28.5nmol/mg of microsomal protein in 30min at 30°C. This corresponds to 104nmol of naphthalene hydroxylated/nmol of cytochrome P-450. This is the highest rate ever reported for housefly and rat liver microsomal preparations. 3. Microsomal fractions prepared by procedures that do not retain the integrity of sarcosomes show the presence in the CO-difference spectrum of a 428nm peak. This cytochrome is associated with sarcosomal microsomes and it may be involved in the inhibition of insect microsomal mixed-function oxidases, although other factors cannot be discarded at present. 4. The inability to show cytochrome P-450 in microsomal fractions isolated from whole houseflies by other procedures may be at least partially due to a masking effect brought about by contamination with the sarcosomal cytochrome.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Agosin M., Scaramelli N., Gil L., Letelier M. E. Some properties of the microsomal system metabolizing DDT in Triatoma infestans. Comp Biochem Physiol. 1969 May;29(2):785–793. doi: 10.1016/0010-406x(69)91629-6. [DOI] [PubMed] [Google Scholar]
- BOOTH J., BOYLAND E. Metabolism of polycyclic compounds. 13. Enzymic hydroxylation of naphthalene by rat-liver microsomes. Biochem J. 1958 Dec;70(4):681–688. doi: 10.1042/bj0700681. [DOI] [PMC free article] [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- OMURA T., SATO R. THE CARBON MONOXIDE-BINDING PIGMENT OF LIVER MICROSOMES. I. EVIDENCE FOR ITS HEMOPROTEIN NATURE. J Biol Chem. 1964 Jul;239:2370–2378. [PubMed] [Google Scholar]
- Perry A. S. Studies on microsomal cytochrome P-450 in resistant and susceptible houseflies. Life Sci. 1970 Mar 22;9(6):335–350. doi: 10.1016/0024-3205(70)90178-5. [DOI] [PubMed] [Google Scholar]
- Schafer J. A., Terriere L. C. Enzymatic and physical factors in house fly resistance to naphthalene. J Econ Entomol. 1970 Jun;63(3):787–792. doi: 10.1093/jee/63.3.787. [DOI] [PubMed] [Google Scholar]
- Schonbrod R. D., Terriere L. C. Improvements in the methods of preparation and storage of house fly microsomes. J Econ Entomol. 1966 Dec;59(6):1411–1413. doi: 10.1093/jee/59.6.1411. [DOI] [PubMed] [Google Scholar]
- WATANABE M. I., WILLIAMS C. M. Mitochondria in the flight muscles of insects. I. Chemical composition and enzymatic content. J Gen Physiol. 1951 May;34(5):675–689. doi: 10.1085/jgp.34.5.675. [DOI] [PMC free article] [PubMed] [Google Scholar]