D. Hughes
Jul 1, 1954
Citations
0
Influential Citations
10
Citations
Journal
The Biochemical journal
Abstract
Among the non-metallic elements which form single covalent bonds, fluorine most nearly approaches hydrogen in atomic weight and size. The effect ofthe substitution of fluorine for hydrogen in molecules of essential metabolites is therefore of interest. This is especially so since it has been shown that monofluoroacetate is transformed into fluorocitrate which in its turn inhibits aconitase and thus blocks the tricarboxylic acid cycle (Peters, 1952). Fluorotyrosine and fluorophenylalanine have been shown to act as antagonists to tyrosine and phenylalanine in Neurospora (Mitchell & Nieman, 1947). More recently, Halvorson & Speigelman (1952) have shown that these two fluoro analogues inhibit adaptation in bacteria. The halogen-substituted nicotinic acids examined in this paper were synthesized for test as therapeutic agents (Minor, Hawkins, Vanderverf & Roe, 1949; Hawkins & Roe, 1949). One of them, namely 5-fluoronicotinic acid was shown to inhibit bacterial growth. It seemed likely that this inhibition was due to the inhibition of cozymase synthesis. This idea has been tested by growth tests as well as by studies of the effect of the analogues on cozymase synthesis in washed suspensions of bacteria as described in a previous paper (Hughes & Williamson, 1952a). The anticipated inhibition of cozymase synthesis by 5-fluoronicotinic acid has been found in three species of bacteria, but it has not been possible to establish definitely the precise point at which the synthesis is blocked.