Estimation of dolichol and cholesterol synthesis in microsomes and peroxisomes isolated from rat liver.
The participation of peroxisomal and microsomal fractions from rat liver in dolichol and cholesterol synthesis was investigated using marker enzymes. Recovery was 8% for peroxisomes and 33% for microsomes, with virtually no cross-contamination between these fractions. Using these data, it was calculated that the peroxisomal branch-point enzyme activities for dolichol and cholesterol biosynthesis, i.e. cis-prenyltransferase and squalene synthase, were 25% and 12%, respectively, of the total homogenate activity. Treatment with mevinolin increased the peroxisomal contribution in the case of both enzymes, to levels almost equal to that of their microsomal counterparts. These results indicate that peroxisomes play a role in the biosynthesis of isoprenoid lipids and that the extent of this participation is increased extensively when peroxisomes are induced by various treatments.
Department of Biochemistry, Arrhenius Laboratories for Natural Sciences, Stockholm University, Sweden.
J
J
Grünler
J M
JM
Olsson
G
G
Dallner
D000818:Animals; D002374:Catalase / Q000378:metabolism; D002784:Cholesterol / Q000096:biosynthesis*; D004286:Dolichols / Q000096:biosynthesis*; D013186:Farnesyl-Diphosphate Farnesyltransferase / Q000378:metabolism; D008148:Lovastatin / Q000494:pharmacology; D008297:Male; D008830:Microbodies / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014503:Urate Oxidase / Q000378:metabolism
D004286:Dolichols; D002784:Cholesterol; D008148:Lovastatin; D002374:Catalase; D014503:Urate Oxidase; D013186:Farnesyl-Diphosphate Farnesyltransferase