The non-linear dependence of cytochrome P450 activity at low microsome concentration
A non-linear decrease in the activity of cytochrome P450-dependent (P450) ethoxyphenoxazone deethylase was observed with intact rat liver and lung microsomal fractions, although all components of the P450 complex were present. Activity was restored by adding pre-heated microsomal membranes or synthe...
Saved in:
Published in | Biochemistry international Vol. 15; no. 5; p. 1033 |
---|---|
Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Australia
01.11.1987
|
Subjects | |
Online Access | Get more information |
Cover
Loading…
Summary: | A non-linear decrease in the activity of cytochrome P450-dependent (P450) ethoxyphenoxazone deethylase was observed with intact rat liver and lung microsomal fractions, although all components of the P450 complex were present. Activity was restored by adding pre-heated microsomal membranes or synthetic phospholipid, or by concentrating the diluted preparation. Aqueous dilution of the microsomal fraction resulted in altered Vmax values, whereas Km(app) values (0.2 microM) were only slightly changed. The results are discussed in terms of the relationship between cytochrome P450 action in model systems and in native microsomal membranes. |
---|---|
ISSN: | 0158-5231 |