title: Conversion from Tryptophan Precursor into Violacein Pigments by a Cell-free System from Chromobacterium violaceum.
abstract: A cell-free system for converting tryptophan precursor into violacein pigments is reported. Crucial factors were the requirements of the reduced nicotinamides as a cofactor and Zn(2+) as a metal ion. Optimal pHs were in the range of 8.5-9.5. The effectiveness of NADH was thirty times lower than that of NADPH at a low concentration of 2mm. The oxygenation mechanism(s) is discussed by using oxygenase inhibitors such as amethopterin, metyrapone, ancymidol, and prohexadione. Metal-chelating agents strongly inhibited the biosynthesis, suggesting that metallo-enzymes are involved in the biosynthesis.
authors.affiliation: a Department of Applied Biological Chemistry, Faculty of Agriculture , Niigata University , Ikarashi, Niigata 950-21 , Japan.
authors.forename: T
authors.initials: T
authors.lastname: Hoshino
authors.affiliation: a Department of Applied Biological Chemistry, Faculty of Agriculture , Niigata University , Ikarashi, Niigata 950-21 , Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yamamoto
keywords: NADPH; cell-free biosynthesis; metalio-enzyme; tryptophan; violacein