A. L. Hunt
May 1, 1959
Citations
1
Influential Citations
28
Citations
Journal
The Biochemical journal
Abstract
The nicotinic acid hydroxylase system of Pseudomonas fluorescens KB 1 has previously been shown to be an adaptive enzyme which hydroxylates nicotinic acid in the C-6 position with the uptake of one molecule of oxygen for two molecules of nicotinic acid (Hughes, 1955). The reaction initiates the breakdown of nicotinic acid to ammonia and formic, acetic, lactic and malic acid according to the reactions described by Behrman & Stanier (1957). In cell-free extracts nicotinic acid is converted quantitatively into 6-hydroxynicotinic acid and this compound is not further metabolized. The hydroxyl group added is derived from water and not molecular oxygen, indicating that the reaction probably involves the addition ofwater followed by dehydrogenation with molecular oxygen as hydrogen acceptor (Hunt, & The enzyme is attached to insoluble particulate components of the cell. This paper is concerned with the purification of the. enzyme, together with the components of an associated electron-transport chain, by deoxycholate extraction of the particles, followed by ammonium sulphate fractionation. Preliminary findings of this work have been com-municated (Hunt, 1958).