title: Expression of microsomal lanosterol 14alpha-demethylase (CYP51) in an engineered soluble monomeric form.
abstract: We prepared a soluble monomeric form of bovine cytochrome P450 lanosterol 14alpha-demethylase (CYP51), which in mammals is a ubiquitously expressed membrane protein of the endoplasmic reticulum. We constructed two variants of bovine CYP51 (bCYP51) with different truncations and modifications in their N-terminal membrane-spanning domains. Both of these were expressed in Escherichia coli at levels of 500nmol/l. The protein variants were purified and tested for the solubility in the absence of detergent. Variant bCYP51-d1 exhibited approximately 10-fold better solubility over variant bCYT51-d2. The bCYP51-d1 eluted as a single peak in size-exclusion chromatography, corresponding to its monomeric form. The activity of bCYP51-d1 is similar to that of recombinant human CYP51 with a non-truncated membrane-spanning region. High solubility and low tendency to non-specific oligomer formation make bCYP51-d1 a promising candidate for successful crystallization, which may finally allow the structural determination of this important mammalian enzyme.
authors.affiliation: Centre for Functional Genomics and Bio-Chips, Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Zaloska 4, SI-1000 Ljubljana, Slovenia.
authors.forename: Matej
authors.initials: M
authors.lastname: Seliskar
authors.forename: Rok
authors.initials: R
authors.lastname: Kosir
authors.forename: Damjana
authors.initials: D
authors.lastname: Rozman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002850:Chromatography, Gel; D003460:Crystallization; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis* / Q000737:chemistry* / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D007654:Ketoconazole / Q000737:chemistry; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000096:biosynthesis* / Q000737:chemistry* / Q000235:genetics; D015202:Protein Engineering; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D012995:Solubility; D058886:Sterol 14-Demethylase
chemical_list: C548418:CYP51A1 protein, human; D011994:Recombinant Proteins; D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases; D058886:Sterol 14-Demethylase; D007654:Ketoconazole