Skip to main content
Log in

Mechanism of irreversible inactivation of phenylalanine-4- and tryptophan-5-hydroxylases by [4-36Cl, 2-14C]p-chlorophenylalanine: A revision

  • Original Articles
  • Published:
Neurochemical Research Aims and scope Submit manuscript

Abstract

Intraperitoneal injection of [4-36Cl, 2-14C]p-chlorophenylalanine (pCPA) (300 mg/kg) in rats revealed absence of chlorine in pure hepatic phenylalanine hydroxyase, while the carbon label appeared as 1–4 moles/mole of [14C]tyrosine in the inactivated phenylalanine and cerebral tryptophan-5-hydroxylase. Crystalline muscle aldolase and tyrosine hydroxylase also revealed the presence of [2-14C]tyrosine from [2-14C]pCPA without inactivating these enzymes. Injection of L-[(U)-14C] tyrosine led to its incorporation into the above enzymes, but to a different degree without altering the enzyme activity. Repeated injections ofp-chlorophenylacetic acid had no effect on phenylalanine or tryptophan-hydroxylase. Administration of pCPA did not change the levels of cerebral biopterins. Reexamination of the effect of cycloheximide on reversing enzymic inactivation by pCPA failed to confirm our earlier observation.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Koe, B. K., andWeissman, A. 1966.P-Chlorophenylalanine: Specific depletor of brain serotonin. J. Pharmacol. Exper. Ther. 154:499–516.

    Google Scholar 

  2. Jequier, E., Lovenberg, W., andSjoerdsma, A. 1967. Tryptophan hydroxylase inhibition. The mechanism by whichp-chlorophenylalanine depletes rat brain serotonin. Molecular Pharmacol. 3:274–278.

    Google Scholar 

  3. Gál, E. M., Roggeveen, A. E., andMillard, S. A. 1970. DL-2-14CP-chlorophenylalanine as an inhibitor of tryptophan-5-hydroxylase. J. Neurochem. 17:1221–1235.

    Google Scholar 

  4. Gál, E. M., andMillard, S. A. 1971. The mechanism of inhibition of hydroxylases in vivo byp-chlorophenylalanine: The effect of cycloheximide. Biochem. Biophys. Acta. 227:32–41.

    Google Scholar 

  5. Kaufman, S. 1962. Phenylalanine hydroxylase. Pages 809–814in J. P. Colowick, andN. O. Kaplan (eds.), Methods of Enzymology, Vol. V, Academic Press, New York.

    Google Scholar 

  6. Gál, E. M., andWhitacre, D. H. 1980. Mechanism of action:p-Chlorophenylalanine (p-CPA) Transact. Am. Soc. Neurochem. 11:76.

    Google Scholar 

  7. Gál, E. M., Hanson, G., andSherman, A. D. 1976. Biopterin I. Profile and quantitation in rat brain. Neurochem. Res. 1:511–523.

    Google Scholar 

  8. Gál, E. M., andPatterson, K. 1973. Rapid nonisotopic assay of tryptophan-5-hydroxylase activity in tissues. Anal. Biochem. 52:625–629.

    Google Scholar 

  9. Shulgin, A. T., andGál, E. M. 1973. New synthesis of 2,5-dihydroxyphenylalanine adapted to isotopic scale. J. Chem. Soc. (London) 1316–1318.

  10. Houghten, R. A., andRapoport, H. 1974. Synthesis of pure L-p-chlorophenylalanine from L-phenylalanine. J. Med. Chem. 17:556–558.

    Google Scholar 

  11. Kaufman, S., andFisher, D. B. 1970. Purification and some physical properties of phenylalanine hydroxylase from rat liver. J. Biol. Chem. 245:(18):4745–4750.

    Google Scholar 

  12. Orr, M. D., Blakley, R. L., andPanagou, D. 1972. Discontinuous buffer systems for analytical and preparative electrophoresis of enzymes on polyacrylamide gels. Anal. Biochem. 45:68–85.

    Google Scholar 

  13. Tong, J. H., andKaufman, S. 1975. Tryptophan hydroxylase. J. Biol. Chem. 250:4152–4158.

    Google Scholar 

  14. Kuczenski, R. 1973. Rat brain tyrosine hydroxylase. J. Biol. Chem. 248:2261–2265.

    Google Scholar 

  15. Kuczenski, R. T., andMandell, A. J. 1972. Regulatory properties of soluble and particulate rat brain tyrosine hydroxylase. J. Biol. Chem. 247:3114–3122.

    Google Scholar 

  16. Suh, B., andBarker, R. 1971. Fluorescence studies of the binding of alkyl and aryl phosphates to rat muscle aldolase. J. Biol. Chem. 246:7041–7050.

    Google Scholar 

  17. Stegink, L. D. 1971. Simultaneous measurement of radioactivity and amino acid composition of physiological fluids during amino acid toxicity studies, Pages 591–594,in E. C. Barton, (ed.), Advances in Automated Analysis, Vol. I, Thurman Assoc. Miami, Florida.

    Google Scholar 

  18. Miller, M. R., McClure, D., andShiman, R. 1976. Mechanism of inactivation of phenylalanine hydroxylase byp-chlorophenylalanine in hepatoma cells in culture. J. Biol. Chem. 251:3677–3684.

    Google Scholar 

  19. Gál, E. M., andSherman, A. D. 1976. Biopterin II. Evidence for cerebral synthesis of 7,8-dihydrobiopterin in vivo and in vitro. Neurochem. Res. 1:627–639.

    Google Scholar 

  20. Brase, D. A. andLoh, H. H. 1976. Studies on the inhibition of phenylalanine hydroxylase activity by p-chlorophenylalanine. Proc. West. Pharmacol. Soc. 19:172–176.

    Google Scholar 

  21. Fisher, D. B., andKaufman, S. 1973. Stimulation of rat liver phenylalanine hydroxylase by lysolecithin and α-chymotrypsin. J. Biol. Chem. 248:4345–4353.

    Google Scholar 

  22. Gál, E. M. 1972. Molecular basis of inhibition of monoxygenases byp-halophenylalanines, Pages 149–163,in E. Costa, andP. Greengard (eds.), Advances in Biochemical Psychopharmacology, Vol. 6, Raven Press, New York.

    Google Scholar 

  23. Jirgenson, A. 1969. Optical rotatory dispersion of proteins and macromolecules. Page 10, Springer-Verlag, New York.

    Google Scholar 

  24. Gál, E. M., Yang, S. L., andMoses, F. 1975. Cerebral monoxygenases: Biochemical and immunological studies. Proc. Int. Soc. Neurochem. 5:24.

    Google Scholar 

  25. Chang, N., Kaufman, S., andMilstein, S. 1979. The mechanism of the irreversible inhibition of rat liver phenylalanine hydroxylase due to treatment withp-chlorophenylalanine. 254:(8):2665–2668.

  26. Munier, R., andCohen, G. N. 1959. Incorporation d'analogues structuraux d'aminoacides dans les proteines bacteriennes au cours de leur synthese in vivo. Biochem. Biophys. Acta. 31:378–391.

    Google Scholar 

  27. Westhead, E. W., andBoyer, P. D. 1961. The incorporation of p-fluorophenylalanine into some rabbit enzymes and other proteins. Biochem. Biophys Acta. 54:145–156.

    Google Scholar 

  28. Forssmann, W. G., andBieger, W. 1973. Biosynthese falscher Proteine: Einbau vonp-chlorophenylalanin in Enzyme des exokrinen Pankreas. Res. exp. Med. 160:1–20.

    Google Scholar 

  29. Dolan, G., andGodin, C. 1966. In vivo formation of tyrosine from p-fluorophenylalanine. Biochem. 5:922–925.

    Google Scholar 

  30. Dunn, T. F., andLeach, F. R. 1967. Incorporation of p-fluorophenylalanine into protein by a cell-free system. J. Biol. Chem. 242:2693–2699.

    Google Scholar 

  31. Gál, E. M. 1974. Syntheticp-halogenophenylalanines and protein synthesis in the brain, Pages 343–359,in Aromatic amino acids in the brain, Ciba Foundation Symposium, Vol. 22, Elsevier Press, Amsterdam.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Gál, E.M., Whitacre, D.H. Mechanism of irreversible inactivation of phenylalanine-4- and tryptophan-5-hydroxylases by [4-36Cl, 2-14C]p-chlorophenylalanine: A revision. Neurochem Res 7, 13–26 (1982). https://doi.org/10.1007/BF00965065

Download citation

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00965065

Keywords

Navigation