Identification of enzyme activity that conjugates indole-3-acetic acid to aspartate in immature seeds of pea (Pisum sativum).
This study describes the first identification of plant enzyme activity catalyzing the conjugation of indole-3-acetic acid to amino acids. Enzymatic synthesis of indole-3-acetylaspartate (IAA-Asp) by a crude enzyme preparation from immature seeds of pea (Pisum sativum) was observed. The reaction yielded a product with the same Rf as IAA-Asp standard after thin layer chromatography. The identity of IAA-Asp was verified by HPLC analysis. IAA-Asp formation was dependent on ATP and Mg2+, and was linear during a 60 min period. The enzyme preparation obtained after poly(ethylene glycol) 6000 fractionation showed optimum activity at pH 8.0, and the temperature optimum for IAA-Asp synthesis was 30 degrees C.
Ostrowski
Maciej
M
Department of Biochemistry, Nicolaus Copernicus University, Institute of General and Molecular Biology, ul. Gagarina 9, 87-100 Toruń, Poland. maciejo@stud.umk.pl
Jakubowska
Anna
A
D001224:Aspartic Acid / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D006863:Hydrogen-Ion Concentration; D007210:Indoleacetic Acids / Q000378:metabolism*; D008025:Ligases / Q000302:isolation & purification / Q000378:metabolism; D018532:Pisum sativum / Q000201:enzymology / Q000378:metabolism*; D010940:Plant Proteins / Q000302:isolation & purification / Q000378:metabolism; D012639:Seeds / Q000201:enzymology / Q000378:metabolism*
D007210:Indoleacetic Acids; D010940:Plant Proteins; D001224:Aspartic Acid; C030737:indoleacetic acid; D008025:Ligases