AROMATIC METABOLISM IN PLANTS. I. A STUDY OF THE PREPHENATE DEHYDROGENASE FROM BEAN PLANTS,

Abstract

Prephenate dehydrogenase (prephenate: NADP(+) oxidoreductase (decarboxylating)) was isolated from cotyledons of wax bean (Phaseolus vulgaris L. var. Bountiful). The enzyme utilizes NADP(+) as an oxidant. The optimum pH for activity is 7.5, and the maximum stability of the enzyme at 22 degrees is achieved in the pH range from 7 to 8. The enzyme is inhibited by sulphydryl complexing compounds. Addition of phenylalanine, tyrosine, or cinnamate did not depress the rate of formation of 4-hydroxyphenylpyruvate. The prephenate dehydrogenase also is present in the cotyledons and the shoots of mung bean (Phaseolus aureus Roxb.). A study was made of the variation in the amount of prephenate dehydrogenase and aromatic amino acid transaminase in developing mung bean plants. The results show that the dehydrogenase is present in largest concentration in the cotyledons 4-5 days after germination has been initiated, and the transaminase reaches the highest level in the shoots after 12-14 days of growth. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jun 14, 1965
Accession Number
AD0631263

Entities

People

  • Fred W. Keeley
  • Oluf L. Gamborg

Tags

DTIC Thesaurus Topics

  • Amino Acids
  • Amino Acids Peptides And Proteins
  • Aromatic Amino Acids
  • Bean Plants
  • Biomolecules
  • Chemical Compounds
  • Cyclic Amino Acids
  • Enzymes
  • Germination
  • Metabolism
  • Oxidoreductases
  • Plants
  • Rate Of Formation
  • Tyrosine
  • Vegetables

Readers

  • Aquatic Ecology
  • Molecular and Cellular Biochemistry