NSDHL, as known as Sterol-4-alpha-carboxylate 3-dehydrogenase, is involved in the production (synthesis) of cholesterol. During cholesterol synthesis, it participates in one of several steps that convert a molecule called lanosterol to cholesterol. Specifically, this enzyme removes a carbon atom and three hydrogen atoms (a methyl group) in the conversion of lanosterol to cholesterol. It is also an important component of cell membranes and myelin, the fatty covering that insulates nerve cells. Recombinant human NSDHL protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography.