title: Development of a bacterial system for high yield expression of fully functional adrenal cytochrome b561.
abstract: Adrenal cytochrome b561 (cyt b561) is the prototypical member of an emerging family of proteins that are distributed widely in vertebrate, invertebrate and plant tissues. The adrenal cytochrome is an integral membrane protein with two b-type hemes and six predicted transmembrane helices. Adrenal cyt b561 is involved in catecholamine biosynthesis, shuttling reducing equivalents derived from ascorbate. We have developed an Escherichia coli system for expression, solubilization and purification of the adrenal cytochrome. The spectroscopic and redox properties of the purified recombinant protein expressed in this prokaryotic system confirm that the cytochrome retains a native, fully functional form over a wide pH range. Mass spectral analysis shows that the N-terminal signal peptide is intact. The new bacterial expression system for cyt b561 offers a sixfold improvement in yield and other substantial advantages over existing insect and yeast cell systems for producing the recombinant cytochrome for structure-function studies.
authors.affiliation: Department of Internal Medicine, University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030, USA. Wen.Liu.2@uth.tmc.edu
authors.forename: Wen
authors.initials: W
authors.lastname: Liu
authors.forename: Corina E
authors.initials: CE
authors.lastname: Rogge
authors.forename: Yury
authors.initials: Y
authors.lastname: Kamensky
authors.forename: Ah-Lim
authors.initials: AL
authors.lastname: Tsai
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Kulmacz
mesh_terms: D000311:Adrenal Glands / Q000378:metabolism*; D001205:Ascorbic Acid / Q000378:metabolism; D003001:Cloning, Molecular; D003573:Cytochrome b Group / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D005822:Genetic Vectors; D006418:Heme / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000737:chemistry
chemical_list: D003573:Cytochrome b Group; D011994:Recombinant Proteins; C023646:cytochrome b561; D006418:Heme; D001205:Ascorbic Acid