Conjugation of cholic acid with taurine and glycine by rat liver peroxisomes.
We have previously shown that rat liver peroxisomes catalyze conversion of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid into cholic acid as the CoA-ester (1). In the present work it is shown that addition of taurine or glycine to the reaction mixture, choloyl-CoA is further converted to taurocholic or glycocholic acid, respectively. The identity of these products was verified by fast atom bombardment-mass spectrometry. The peroxisomal fraction catalyzed conjugation of cholic acid with taurine (22.3 nmol X mg-1 X h-1) or glycine (18.6 nmol X mg-1 X h-1) at rates twice those observed with the microsomal fraction. The results indicate that conjugation of newly formed bile acids may be an important function of liver peroxisomes.
D000818:Animals; D002793:Cholic Acids / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003065:Coenzyme A / Q000378:metabolism; D005998:Glycine / Q000378:metabolism; D006000:Glycocholic Acid / Q000378:metabolism*; D008099:Liver / Q000648:ultrastructure*; D008297:Male; D008830:Microbodies / Q000378:metabolism*; D008862:Microsomes, Liver / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013054:Spectrophotometry, Atomic; D013654:Taurine / Q000378:metabolism; D013656:Taurocholic Acid / Q000378:metabolism*
D002793:Cholic Acids; D013654:Taurine; D013656:Taurocholic Acid; D006000:Glycocholic Acid; D003065:Coenzyme A; D005998:Glycine