Effects of cholecalciferol (vitamin D3)-binding proteins and anti-cytochrome b5 immunoglobulin on cholecalciferol 25-hydroxylase activities of rabbit liver microsomes and mitochondria.
The effects of cholecalciferol (vitamin D3)-binding proteins and anti-cytochrome b5 immunoglobulin were studied on vitamin D3 25-hydroxylase activities of microsomes and mitochondria under various experimental conditions. The vitamin D3-binding protein in serum as well as in the liver postmicrosomal supernatant (cellular vitamin D3-binding protein), but not serum albumin and ovalbumin, stimulated vitamin D3 25-hydroxylase activities of microsomes and mitochondria. The optimum pH range was from 7.3 to 8.0. Anti-cytochrome b5 immunoglobulin did not affect microsomal vitamin D3 25-hydroxylase activity.
D000818:Animals; D000936:Antigen-Antibody Complex; D002417:Cattle; D053493:Cholestanetriol 26-Monooxygenase; D003573:Cytochrome b Group / Q000378:metabolism*; D015786:Cytochromes b5; D006863:Hydrogen-Ion Concentration; D007074:Immunoglobulin G; D007700:Kinetics; D008862:Microsomes, Liver / Q000201:enzymology*; D008930:Mitochondria, Liver / Q000201:enzymology*; D009994:Osmolar Concentration; D011817:Rabbits; D012709:Serum Albumin / Q000494:pharmacology; D013250:Steroid Hydroxylases / Q000378:metabolism*; D014807:Vitamin D / Q000494:pharmacology*; D014809:Vitamin D-Binding Protein / Q000378:metabolism / Q000494:pharmacology*
D000936:Antigen-Antibody Complex; D003573:Cytochrome b Group; D007074:Immunoglobulin G; D012709:Serum Albumin; D014809:Vitamin D-Binding Protein; D014807:Vitamin D; D015786:Cytochromes b5; D013250:Steroid Hydroxylases; D053493:Cholestanetriol 26-Monooxygenase