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.
Similar content being viewed by others
References
Koe, B. K., andWeissman, A. 1966.P-Chlorophenylalanine: Specific depletor of brain serotonin. J. Pharmacol. Exper. Ther. 154:499–516.
Jequier, E., Lovenberg, W., andSjoerdsma, A. 1967. Tryptophan hydroxylase inhibition. The mechanism by whichp-chlorophenylalanine depletes rat brain serotonin. Molecular Pharmacol. 3:274–278.
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.
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.
Kaufman, S. 1962. Phenylalanine hydroxylase. Pages 809–814in J. P. Colowick, andN. O. Kaplan (eds.), Methods of Enzymology, Vol. V, Academic Press, New York.
Gál, E. M., andWhitacre, D. H. 1980. Mechanism of action:p-Chlorophenylalanine (p-CPA) Transact. Am. Soc. Neurochem. 11:76.
Gál, E. M., Hanson, G., andSherman, A. D. 1976. Biopterin I. Profile and quantitation in rat brain. Neurochem. Res. 1:511–523.
Gál, E. M., andPatterson, K. 1973. Rapid nonisotopic assay of tryptophan-5-hydroxylase activity in tissues. Anal. Biochem. 52:625–629.
Shulgin, A. T., andGál, E. M. 1973. New synthesis of 2,5-dihydroxyphenylalanine adapted to isotopic scale. J. Chem. Soc. (London) 1316–1318.
Houghten, R. A., andRapoport, H. 1974. Synthesis of pure L-p-chlorophenylalanine from L-phenylalanine. J. Med. Chem. 17:556–558.
Kaufman, S., andFisher, D. B. 1970. Purification and some physical properties of phenylalanine hydroxylase from rat liver. J. Biol. Chem. 245:(18):4745–4750.
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.
Tong, J. H., andKaufman, S. 1975. Tryptophan hydroxylase. J. Biol. Chem. 250:4152–4158.
Kuczenski, R. 1973. Rat brain tyrosine hydroxylase. J. Biol. Chem. 248:2261–2265.
Kuczenski, R. T., andMandell, A. J. 1972. Regulatory properties of soluble and particulate rat brain tyrosine hydroxylase. J. Biol. Chem. 247:3114–3122.
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.
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.
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.
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.
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.
Fisher, D. B., andKaufman, S. 1973. Stimulation of rat liver phenylalanine hydroxylase by lysolecithin and α-chymotrypsin. J. Biol. Chem. 248:4345–4353.
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.
Jirgenson, A. 1969. Optical rotatory dispersion of proteins and macromolecules. Page 10, Springer-Verlag, New York.
Gál, E. M., Yang, S. L., andMoses, F. 1975. Cerebral monoxygenases: Biochemical and immunological studies. Proc. Int. Soc. Neurochem. 5:24.
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.
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.
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.
Forssmann, W. G., andBieger, W. 1973. Biosynthese falscher Proteine: Einbau vonp-chlorophenylalanin in Enzyme des exokrinen Pankreas. Res. exp. Med. 160:1–20.
Dolan, G., andGodin, C. 1966. In vivo formation of tyrosine from p-fluorophenylalanine. Biochem. 5:922–925.
Dunn, T. F., andLeach, F. R. 1967. Incorporation of p-fluorophenylalanine into protein by a cell-free system. J. Biol. Chem. 242:2693–2699.
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.
Author information
Authors and Affiliations
Rights 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
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00965065