Abstract
The bioactivation of S-(2-chloro-1,1,2-trifluoroethyl)-L-cysteine (CTFC) was studied with purified bovine kidney cysteine conjugate beta-lyase and with N-dodecylpyridoxal bromide in cetyltrimethylammonium bromide micelles as a pyridoxal model system. The beta-lyase and the pyridoxal model system converted CTFC to chlorofluoroacetic acid and inorganic fluoride, which were identified by 19F NMR spectrometry. 2-Chloro-1,1,2-trifluoroethanethiol and chlorofluorothionoacetyl fluoride were formed as metabolites of CTFC and were trapped with benzyl bromide and diethylamine, respectively, to yield benzyl 2-chloro-1,1,2-trifluoroethyl sulfide and N,N-diethyl chlorofluorothioacetamide, which were identified by gas chromatography/mass spectrometry. The bioactivation mechanism of CTFC therefore involves the initial formation of the unstable thiol 2-chloro-1,1,2-trifluoroethanethiol, which loses hydrogen fluoride to form the acylating agent chlorofluorothionoacetyl fluoride; hydrolysis of the thionoacyl fluoride affords the stable, terminal metabolites chlorofluoroacetic acid and inorganic fluoride. The intermediate acylating agent and chlorofluoroacetic acid may contribute to the cytotoxic effects of CTFC.
Full text
PDF




Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Anders M. W., Elfarra A. A., Lash L. H. Cellular effects of reactive intermediates: nephrotoxicity of S-conjugates of amino acids. Arch Toxicol. 1987;60(1-3):103–108. doi: 10.1007/BF00296959. [DOI] [PubMed] [Google Scholar]
- Banki K., Elfarra A. A., Lash L. H., Anders M. W. Metabolism of S-(2-chloro-1,1,2-trifluoroethyl)-L-cysteine to hydrogen sulfide and the role of hydrogen sulfide in S-(2-chloro-1,1,2-trifluoroethyl)-L-cysteine-induced mitochondrial toxicity. Biochem Biophys Res Commun. 1986 Jul 31;138(2):707–713. doi: 10.1016/s0006-291x(86)80554-x. [DOI] [PubMed] [Google Scholar]
- Cooper A. J. Purification of soluble and mitochondrial glutamine transaminase K from rat kidney. Use of a sensitive assay involving transamination between L-phenylalanine and alpha-keto-gamma-methiolbutyrate. Anal Biochem. 1978 Sep;89(2):451–460. doi: 10.1016/0003-2697(78)90374-3. [DOI] [PubMed] [Google Scholar]
- Crabb D. W., Yount E. A., Harris R. A. The metabolic effects of dichloroacetate. Metabolism. 1981 Oct;30(10):1024–1039. doi: 10.1016/0026-0495(81)90105-0. [DOI] [PubMed] [Google Scholar]
- Dekant W., Metzler M., Henschler D. Identification of S-1,2,2-trichlorovinyl-N-acetylcysteine as a urinary metabolite of tetrachloroethylene: bioactivation through glutathione conjugation as a possible explanation of its nephrocarcinogenicity. J Biochem Toxicol. 1986 Jun;1(2):57–72. doi: 10.1002/jbt.2570010206. [DOI] [PubMed] [Google Scholar]
- Dekant W., Metzler M., Henschler D. Identification of S-1,2-dichlorovinyl-N-acetyl-cysteine as a urinary metabolite of trichloroethylene: a possible explanation for its nephrocarcinogenicity in male rats. Biochem Pharmacol. 1986 Aug 1;35(15):2455–2458. doi: 10.1016/0006-2952(86)90039-0. [DOI] [PubMed] [Google Scholar]
- Dekant W., Vamvakas S., Berthold K., Schmidt S., Wild D., Henschler D. Bacterial beta-lyase mediated cleavage and mutagenicity of cysteine conjugates derived from the nephrocarcinogenic alkenes trichloroethylene, tetrachloroethylene and hexachlorobutadiene. Chem Biol Interact. 1986 Oct 15;60(1):31–45. doi: 10.1016/0009-2797(86)90015-3. [DOI] [PubMed] [Google Scholar]
- Dohn D. R., Anders M. W. Assay of cysteine conjugate beta-lyase activity with S-(2-benzothiazolyl)cysteine as the substrate. Anal Biochem. 1982 Mar 1;120(2):379–386. doi: 10.1016/0003-2697(82)90361-x. [DOI] [PubMed] [Google Scholar]
- Dohn D. R., Leininger J. R., Lash L. H., Quebbemann A. J., Anders M. W. Nephrotoxicity of S-(2-chloro-1,1,2-trifluoroethyl)glutathione and S-(2-chloro-1,1,2-trifluoroethyl)-L-cysteine, the glutathione and cysteine conjugates of chlorotrifluoroethene. J Pharmacol Exp Ther. 1985 Dec;235(3):851–857. [PubMed] [Google Scholar]
- Dohn D. R., Quebbemann A. J., Borch R. F., Anders M. W. Enzymatic reaction of chlorotrifluoroethene with glutathione: 19F NMR evidence for stereochemical control of the reaction. Biochemistry. 1985 Sep 10;24(19):5137–5143. doi: 10.1021/bi00340a027. [DOI] [PubMed] [Google Scholar]
- Elfarra A. A., Anders M. W. Renal processing of glutathione conjugates. Role in nephrotoxicity. Biochem Pharmacol. 1984 Dec 1;33(23):3729–3732. doi: 10.1016/0006-2952(84)90032-7. [DOI] [PubMed] [Google Scholar]
- Elfarra A. A., Lash L. H., Anders M. W. Alpha-ketoacids stimulate rat renal cysteine conjugate beta-lyase activity and potentiate the cytotoxicity of S-(1,2-dichlorovinyl)-L-cysteine. Mol Pharmacol. 1987 Feb;31(2):208–212. [PubMed] [Google Scholar]
- Koga N., Inskeep P. B., Harris T. M., Guengerich F. P. S-[2-(N7-guanyl)ethyl]glutathione, the major DNA adduct formed from 1,2-dibromoethane. Biochemistry. 1986 Apr 22;25(8):2192–2198. doi: 10.1021/bi00356a051. [DOI] [PubMed] [Google Scholar]
- Livesey J. C., Anders M. W., Langvardt P. W., Putzig C. L., Reitz R. H. Stereochemistry of the glutathione-dependent biotransformation of vicinal-dihaloalkanes to alkenes. Drug Metab Dispos. 1982 May-Jun;10(3):201–204. [PubMed] [Google Scholar]
- Potter C. L., Gandolfi A. J., Nagle R., Clayton J. W. Effects of inhaled chlorotrifluoroethylene and hexafluoropropene on the rat kidney. Toxicol Appl Pharmacol. 1981 Jul;59(3):431–440. doi: 10.1016/0041-008x(81)90295-7. [DOI] [PubMed] [Google Scholar]
- Rannug U., Sundvall A., Ramel C. The mutagenic effect of 1,2-dichloroethane on Salmonella typhimurium I. Activation through conjugation with glutathion in vitro. Chem Biol Interact. 1978 Jan;20(1):1–16. doi: 10.1016/0009-2797(78)90076-5. [DOI] [PubMed] [Google Scholar]
- Ricci G., Nardini M., Federici G., Cavallini D. The transamination of L-cystathionine, L-cystine and related compounds by a bovine kidney transaminase. Eur J Biochem. 1986 May 15;157(1):57–63. doi: 10.1111/j.1432-1033.1986.tb09637.x. [DOI] [PubMed] [Google Scholar]
- Stevens J. L., Robbins J. D., Byrd R. A. A purified cysteine conjugate beta-lyase from rat kidney cytosol. Requirement for an alpha-keto acid or an amino acid oxidase for activity and identity with soluble glutamine transaminase K. J Biol Chem. 1986 Nov 25;261(33):15529–15537. [PubMed] [Google Scholar]
- Whitehouse S., Cooper R. H., Randle P. J. Mechanism of activation of pyruvate dehydrogenase by dichloroacetate and other halogenated carboxylic acids. Biochem J. 1974 Sep;141(3):761–774. doi: 10.1042/bj1410761. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Whitford G. M., Taves D. R. Fluoride-induced diuresis: renal-tissue solute concentrations, functional, hemodynamic, and histologic correlates in the rat. Anesthesiology. 1973 Oct;39(4):416–427. [PubMed] [Google Scholar]
