1887

Abstract

Association patterns and regulatory properties of chorismate mutase, prephenate dehydratase and prephenate dehydrogenase from ATCC 15926 were studied. Prephenate dehydrogenase (molecular weight 95000) was separated by Sephadex G-100 chromatography from both the chorismate mutase–prephenate dehydratase I complex (molecular weight 75000) and from a second, low molecular weight prephenate dehydratase (prephenate dehydratase II; molecular weight 30000). The chorismate mutase-prephenate dehydratase complex persisted after DEAE-Sephadex A-50 chromatography. With the exception of prephenate dehydratase II, enzyme activities were influenced by end-products. Chorismate mutase was competitively inhibited by -phenylalanine ( = 3·5 ). Prephenate dehydratase I was inhibited by -phenylalanine ( = 8 ) and activated by -tyrosine ( = 5 ). Prephenate dehydrogenase was feedback-inhibited by -tyrosine. Substrate saturation curves of chorismate mutase and of prephenate dehydratase II were hyperbolic with values of 0·31 m for chorismate and 0·015 m for prephenate, respectively. The substrate saturation curve of the complexed prephenate dehydratase I was sigmoid; a value of 0·18 m was calculated for prephenate. Chorismate mutase, prephenate dehydratase and prephenate dehydrogenase were not repressed by aromatic amino acids.

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1980-03-01
2024-04-28
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References

  1. Ahmed S. I., Campbell J. J. R. 1973; A bifunctional enzyme in Pseudomonas aeruginosa: a new pattern in the organization of enzymes concerned with phenylalanine and tyrosine biosynthesis. Journal of Bacteriology 115:205–212
    [Google Scholar]
  2. Andrews P. 1964; Estimation of the molecular weights of proteins by Sephadex gel-filtration. Biochemical Journal 91:222–233
    [Google Scholar]
  3. Calhoun D. H., Pierson D. L., Jensen R. A. 1973; Channel-shuttle mechanism for the regulation of phenylalanine and tyrosine synthesis at a metabolic branch point in Pseudomonas aeruginosa. Journal of Bacteriology 113:241–251
    [Google Scholar]
  4. Cerutti P., Guroff G. 1965; Enzymatic formation of phenylpyruvic acid in Pseudomonas sp. (ATCC 11299a) and its regulation. Journal of Biological Chemistry 240:3034–3038
    [Google Scholar]
  5. Cotton R. G. H., Gibson F. 1965; The biosynthesis of phenylalanine and tyrosine: enzymes converting chorismic acid into prephenic acid and their relationships to prephenate dehydratase and prephenate dehydrogenase. Biochimica et biophysica acta 100:76–88
    [Google Scholar]
  6. Cotton R. C. H., Gibson F. 1967; The biosynthesis of tyrosine in Aerobacter aerogenes: partial purification of the T protein. Biochimica et biophysica acta 147:222–237
    [Google Scholar]
  7. Cotton R. G. H., Gibson F. 1970; Tyrosine and phenylalanine biosynthesis: the T and P proteins (Aerobacter aerogenes), chorismate mutase (Pisum sativum). Methods in Enzymology 17A:564–574
    [Google Scholar]
  8. Dayan J., Sprinson D. B. 1970; Preparation of prephenic acid. Methods in Enzymology 17A:559–561
    [Google Scholar]
  9. Fahrney D. E., Gold A. M. 1963; Sulfonyl fluorides as inhibitors of esterases. I. Rates of reaction with acetylcholinesterase, α-chymo-trypsin and trypsin. Journal of the American Chemical Society 85:997–1000
    [Google Scholar]
  10. Gibson F. 1970; Preparation of chorismic acid. Methods in Enzymology 17A:362–364
    [Google Scholar]
  11. Koshland D. E.Jr Némethy G., Filmer D. 1966; Comparison of experimental binding data and theoretical models in proteins containing subunits. Biochemistry 5:365–385
    [Google Scholar]
  12. Layne E. 1957; Spectrometric and turbidimetric methods for measuring proteins. Methods in Enzymology 3:447–454
    [Google Scholar]
  13. Lingens F. 1968; The biosynthesis of aromatic amino acids and its regulation. Angewandte Chemie (International Edition in English) 7:350–360
    [Google Scholar]
  14. Patel N., Pierson D. L., Jensen R. A. 1977; Dual enzymatic routes to l-tyrosine and l-phenylalanine via pretyrosine in Pseudomonas aeruginosa. Journal of Biological Chemistry 252:5839–5846
    [Google Scholar]
  15. Stenmark-Cox S., Jensen R. A. 1975; Prephenate dehydrogenase from Pseudomonas aeruginosa is a regulated component of the channel-shuttle mechanism controlling tyrosine-phenylalanine synthesis. Archives of Biochemistry and Biophysics 167:540–546
    [Google Scholar]
  16. Waltho J. A. 1973; Regulation of phenylalanine biosynthesis in Pseudomonas aeruginosa. Biochimica et biophysica acta 320:232–241
    [Google Scholar]
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