7.1.1.1 - 7.1.1.1 DEAE-Sepharose column chromatography and hydroxyapatite column chromatography 7.1.1.1 detergent-solubilized transhydrogenase, from isolated mitochondrial membranes, purified to apparent homogeneity using ion exchange and hydroxylapatite chromatographies. The isolated enzyme catalyzes neither NADH->NADP+ nor NADH->NAD+ transhydrogenations 7.1.1.1 fusion protein using His-tag and on calmodulin-sepharose 7.1.1.1 His-tagged H91E mutant enzyme 7.1.1.1 Ni-NTA resin column chromatography 7.1.1.1 phenyl-Sepharose column chromatography and DEAE-Trisacryl M column chromatography 7.1.1.1 purification of bacterially expressed, recombinant membrane protein fused with calmodulin-binding domains. This method allows isolation of the protein fusions in a single chromatography step using elution with the calcium chelating agent EDTA. Unlike purification of His-tagged proteins on nickel chelate, it is not sensitive to the presence of strong reducing agents (e.g., DTT). The protocol involves disruption of host bacteria by sonication, sedimentation of membranes by differential centrifugation, solubilization of membrane proteins and affinity chromatography on calmodulin-agarose. To achieve maximum purity and yield, the use of a combination of non-ionic and anionic detergents is suggested. Purification takes two working days, with an overnight wash of the column to increase the purity of the product 7.1.1.1 Q-Sepharose column chromatography and Mono Q column chromatography 7.1.1.1 Q-Sepharose column chromatography, and butyl Toyopearl column chromatography 7.1.1.1 recombinant domain I 7.1.1.1 recombinant domain I and recombinant E155W and Y171W mutant domain III 7.1.1.1 recombinant domains I and III 7.1.1.1 recombinant protein 7.1.1.1 recombinant proteins 7.1.1.1 recombinant wild-type, T393C, R425C, G430C and A432C mutant domain III 7.1.1.1 the recombinant enzyme is purified by pre-extraction of the membranes with sodium cholate and Triton X-100, solubilization of the enzyme with sodium deoxycholate in the presence of 1 M potassium chloride, and centrifugation through a 1.1 M sucrose solution. The wild type enzyme is purified by phenyl Sepharose column chromatography, DEAE-Bio-Gel A column chromatography, and NAD+ agarose column chromatography