Characterization and crystallization of mouse aldehyde oxidase 3: from mouse liver to Escherichia coli heterologous protein expression.

摘要: Aldehyde oxidase (AOX) is characterized by a broad substrate specificity, oxidizing aromatic azaheterocycles, such as N 1 -methylnicotinamide and N-methylphthalazinium, or aldehydes, benzaldehyde, retinal, vanillin. In the past decade, AOX has been recognized increasingly to play an important role in metabolism of drugs through its complex cofactor content, tissue distribution, recognition. humans, only one gene (AOX1) present, but mouse other mammals different homologs were identified. The multiple isoforms are expressed tissue-specifically organisms, it believed that they recognize distinct substrates carry out physiological tasks. dimer with molecular mass approximately 300 kDa, each subunit homodimeric enzyme contains four cofactors: molybdenum cofactor, two [2Fe-2S] clusters, FAD. We purified homolog from liver (mAOX3) established system for heterologous expression mAOX3 Escherichia coli. enzymes compared. Both proteins show same characteristics catalytic properties, difference recombinant protein was 30% active form, whereas native 100% active. Spectroscopic characterization showed FeSII not assembled completely mAOX3. addition, both crystallized. best crystals diffracted beyond 2.9 A. belong space group P1, dimers present unit cell.