The role of a 5alpha-hydroxylated intermediate in the formation of the 5, 6-double bond in cholesterol biosynthesis.
If the biological conversion of cholest-7-en-3beta-ol (I) into cholesterol (IV) occurred thorugh the intermediacy of cholest-7-ene-3beta,5alpha-diol (II) then the factor(s) adversely affecting the convwesion of the 5alpha-hydroxy sterol (II) into cholesterol must at least equally adversely affect the formation of cholesterol from cholest-7-en-3beta-ol. By using partial denaturation techniquws and dual-labelled precursors it was shown that the enzyme system responsible for the conversion of the 5alpha-hydroxy sterol (II) into cholesterol denatured faster than that for the corresponding conversion from cholest-7-en-3beta-ol (I).
D000818:Animals; D002776:Cholestanes / Q000096:biosynthesis; D002782:Cholestenes / Q000378:metabolism*; D002784:Cholesterol / Q000096:biosynthesis*; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism; D051381:Rats; D013261:Sterols / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism
D002776:Cholestanes; D002782:Cholestenes; D013261:Sterols; D002784:Cholesterol