Date of Award

1989

Publication Type

Doctoral Thesis

Degree Name

Ph.D.

Department

Chemistry and Biochemistry

Keywords

Chemistry, Biochemistry.

Rights

info:eu-repo/semantics/openAccess

Abstract

Uniformly carbon-14-labelled 4-deoxy-4-fluoro-D-glucose (D-(U-$\sp{14}$C) 4FG) is synthesized for the first time and used to follow the fate of 4-deoxy-4-fluoro-D-glucose (4FG) in Pseudomonas putida. Following a 24-hour incubation of a suspension of glucose-grown whole cells of P. putida with 1 millimolar(mM) D- (U-$\sp{14}$C) 4FG under conditions giving a 95% release of F$\sp-$, less than 1% of the radiolabel is found to be covalently associated with the peptidoglycan present in the cell-envelope fraction, more than 50% of the radiolabel accumulates in the suspending medium, and as much as 5% of the radiolabel is recovered as a volatile product which appears to be $\sp{14}$CO$\sb2$. Analysis of the radiolabelled cell-envelope fraction by gel filtration gives no evidence that the peptidoglycan-associated radiolabel is incorporated into protein. When the suspending medium is analyzed by borate anion-exchange column chromatography, the radiolabel is resolved into two components: (1) a poorly retained minor-peak metabolite; and (2) a more strongly retained major-peak metabolite which contains 90% of the radiolabel recovered in these two metabolites. Isolation of the major-peak metabolite by preparative borate anion-exchange chromatography yields a single radiolabelled product which appears to be pure by thin-layer chromatographic analysis. This radiolabelled product is identified as 2,3-dideoxyribonic acid by proton and carbon-13 nuclear magnetic resonance (NMR) spectroscopy and mass spectrometric analyses. This identification was later confirmed by synthesizing the sodium salt of 2,3-dideoxyribonic acid and showing that the proton and carbon-13 NMR spectra were identical to those obtained for the isolated major-peak metabolite. A similar isolation and thin-layer chromatographic analysis of the minor-peak metabolite yields an impure product which is tentatively identified as a deoxycarbohydrate derivative. Following a 24-hour incubation of a crude outer-membrane preparation derived from glucose-grown P. putida with 1 mM D- (U-$\sp{14}$C) 4FG under conditions giving a 10% release of F$\sp-$, all of the radiolabel is recovered in the suspending medium. Analysis of the suspending medium by borate anion-exchange chromatography reveals that all of the radiolabelled 4FG is converted to two highly anionic, possibly phosphorylated, components: (1) a major component which is probably a fluorinated metabolite; and (2) a minor component which is probably a non-fluorinated metabolite. Both metabolites differ from the metabolites derived from whole-cell incubations and have retentions that are probably characteristic of phosphorylated aldonic acids. The results of this study, especially the formation of 2,3-dideoxyribonic acid, implicate an intracellular pathway in the metabolism of 4FG. The mechanism by which this occurs is presented and discussed.Dept. of Chemistry and Biochemistry. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1989 .S275. Source: Dissertation Abstracts International, Volume: 50-03, Section: B, page: 0943. Thesis (Ph.D.)--University of Windsor (Canada), 1989.

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