Document Detail

Distribution and nature of epoxide hydrolase activity in subcellular organelles of mouse liver.
MedLine Citation:
PMID:  3083822     Owner:  NLM     Status:  MEDLINE    
Mouse liver light and heavy mitochondrial fractions contain significant epoxide hydrolase activity in addition to that present in the cytosol and microsomes. As the mitochondrial fraction itself contains a number of subfractions, experiments were designed to determine the localization of the epoxide hydrolase activity in these subfractions. Subcellular fractions were prepared using livers from 6- to 8-week-old Swiss-Webster male mice. Using trans-stilbene oxide (TSO) as substrate, the highest activity was localized in the cytosolic fraction, followed by the light mitochondrial fraction. Subfractionation of the light mitochondrial fraction by isopycnic sucrose density gradient resulted in the separation of mitochondria from peroxisomes as monitored by marker enzymes. The separation of these two subcellular organelles was also confirmed by the electron microscopic studies. Distribution of TSO-hydrolase activity in the sucrose density gradient fractions closely resembled the activity distribution of the peroxisomal markers catalase and urate oxidase, but significant activity was also found in mitochondria. Treatment of mice with clofibrate selectively induced TSO-hydrolase in the cytosol without affecting this enzyme activity in the peroxisomal fraction. There was no difference in the distribution pattern of TSO-hydrolase and marker enzymes in sucrose density gradients of mitochondrial fractions from clofibrate-treated and control mice. The epoxide hydrolase activity in the peroxisomes is immunologically similar to, and also has the same molecular weight as, the cytosolic epoxide hydrolase.
S Kaur; S S Gill
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Biochemical pharmacology     Volume:  35     ISSN:  0006-2952     ISO Abbreviation:  Biochem. Pharmacol.     Publication Date:  1986 Apr 
Date Detail:
Created Date:  1986-05-14     Completed Date:  1986-05-14     Revised Date:  2009-11-19    
Medline Journal Info:
Nlm Unique ID:  0101032     Medline TA:  Biochem Pharmacol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  1299-308     Citation Subset:  IM    
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MeSH Terms
Centrifugation, Density Gradient
Chemical Precipitation
Clofibrate / pharmacology
Cytosol / enzymology
Epoxide Hydrolases / analysis*,  immunology,  physiology
Epoxy Compounds / metabolism
Liver / drug effects,  enzymology*
Microbodies / enzymology
Mitochondria, Liver / enzymology
Monoamine Oxidase / analysis
Proteins / analysis
Stilbenes / metabolism
Succinate Dehydrogenase / analysis
Grant Support
Reg. No./Substance:
0/Epoxy Compounds; 0/Proteins; 0/Stilbenes; 17619-97-5/stilbene oxide; 637-07-0/Clofibrate; EC Dehydrogenase; EC Oxidase; EC 3.3.2.-/Epoxide Hydrolases

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