|Budget Amount *help
¥3,200,000 (Direct Cost : ¥3,200,000)
Fiscal Year 1998 : ¥1,100,000 (Direct Cost : ¥1,100,000)
Fiscal Year 1997 : ¥2,100,000 (Direct Cost : ¥2,100,000)
Retinoic acid is a lipoactivator and it play many important roles of cell differentiation, morphorogenesis, embryogenesis and hierarchy action of gene expression. We have found that retinoic acid synthasses are at least three enzymes in rabbit liver. Namely,
their enzymes are cytochrome P-450 1A1-linked monooxygenase system of rabbit liver microsomes, retinal oxidase and NADP^+-linked retinal dehydrogenase of rabbit liver cytosol, and the sequences of base and amino acid residues of these retinoic acid synthases were determined using by probes of partial amino acid sequences of their enzymes. The results demonstrated that retinal oxidase (EC 1,2,3,11) and aldehyde oxidase (EC 1,2,3.1) are a same and single oxidase. The homologies of amino acid residues of the rabbit and mouse retinal oxidases were 82%. The retinal oxidases are flavoenzymes and have FAD as coenzymes and the molecular weights were apparently 300 KDa and compsed of two subunits. The retinal oxidases are metal chelating enzymes of molibdenum and iron. These large molecular and metal chelating flavoenzyme could not be expressed previously in E.coli, but we succeeded to express the retinal oxidase in E.coli. In addition, we also expressed the NADP^+-linked retinal dehydrogenase. These enzymatic properties will be characterized in near future.