Normal activity of C27-steroid 26-hydroxylase in cultured sitosterolaemia fibroblasts.
The primary defect in sitosterolaemia is unknown. In some patients excretion of bile alcohols is increased, and it has been suggested that the defect is located to some step in the biosynthesis of bile acids. The activity of C27-steroid 26-hydroxylase was measured in cultured skin fibroblasts from a sitosterolaemic patient. The same assay was used as before in demonstrating deficiency of this enzyme activity in cerebrotendinous xanthomatosis (CTX), a disease in which high excretion of bile alcohols is typical. The substrate, 5 beta-cholestane-3 alpha,7 alpha,12 alpha-triol, was 26-hydroxylated to the same extent in the patient cells as in those of healthy controls. Thus, the sitosterolaemia cells have a normal activity of this enzyme.
Institute of Clinical Biochemistry, University of Oslo, Rikshospitalet, Norway.
K M
KM
Boberg
I
I
Björkhem
S
S
Skrede
D001927:Brain Diseases / Q000201:enzymology; D002478:Cells, Cultured; D002648:Child; D053493:Cholestanetriol 26-Monooxygenase; D002851:Chromatography, High Pressure Liquid; D005347:Fibroblasts / Q000201:enzymology*; D006801:Humans; D008297:Male; D012855:Sitosterols / Q000097:blood*; D013250:Steroid Hydroxylases / Q000378:metabolism*; D014973:Xanthomatosis / Q000201:enzymology
D012855:Sitosterols; D013250:Steroid Hydroxylases; C506831:CYP27A1 protein, human; D053493:Cholestanetriol 26-Monooxygenase