W. H. Bowman, M. F. Mallette
Dec 1, 1966
Citations
0
Influential Citations
3
Citations
Journal
Archives of Biochemistry and Biophysics
Abstract
Abstract The amino acid analog p -fluorophenylalanine was shown to be metabolized by nitrogen-deficient suspensions of Escherichia coli . Three major metabolic products appeared in extracts of the incubation medium. The data indicated that these products were all monocarboxylic acids having the aromatic ring intact. Functional group analysis, ultraviolet spectroscopy, and co-chromatography showed that one of the metabolic products probably was p -fluorophenylacetic acid. Comparative chemical studies, functional group analysis, and mass spectrometry suggested tentatively that a second product was p -fluorophenylpyruvic acid. The third product remains to be identified. Biological studies indicated that only one isomer of the dl -fluorophenylalanine mixture was metabolized. The metabolism by nitrogen-deficient cultures did not appear to be aimed solely at maintaining a threshold level of nitrogen. Furthermore, the analog was metabolized in a qualitatively similar manner both in the presence and absence of another exogenous source of nitrogen. p -Fluorophenylacetic acid, at a molar concentration equivalent to that at which p -fluorophenylalanine provoked a linear rate of growth, was without apparent effect on the normal exponential rate of growth. However, since no permeability data are available, the significance of this result with respect to possible biological effects of the metabolic products derived from fluorophenylalanine cannot be evaluated. Nevertheless, the formation of these products must be considered when interpreting data obtained from experiments employing p -fluorophenylalanine as a metabolic inhibitor.