Source:http://linkedlifedata.com/resource/umls/id/C0008396
MSH: A membrane-bound cytochrome P450 enzyme that catalyzes the 7-alpha-hydroxylation of CHOLESTEROL in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP7, converts cholesterol to 7-alpha-hydroxycholesterol which is the first and rate-limiting step in the synthesis of BILE ACIDS.,NCI: Encoded by human CYP7A1 Gene (Cytochrome P450 Family), 504-aa 58-kDa Cytochrome P450 7A1 is an endoplasmic reticulum membrane-bound P450 heme-thiolate monooxygenase in the liver that catalyzes the first (rate-limiting) reaction in the cholesterol catabolic pathway: cholesterol conversion to bile acids, the major site of regulation of bile acid synthesis and the primary mechanism for removal of cholesterol from the body. P450 enzymes catalyze reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. (NCI)