Polyamine synthesis in plants. Purification and properties of amidinotransferase from soybean ( Glycine max) axes

• Published in: Phytochemistry (Oxford) 2002-12, Vol.61 (7), p.781-789
• Main Authors: Lee, Geun Taek, Kim, Woo Jeung, Cho, Young Dong
• Format: Article
• Language: English
• Subjects: Amidinotransferase; Amidinotransferases - chemistry; Amidinotransferases - isolation & purification; Amidinotransferases - metabolism; Arginine - chemistry; Arginine - metabolism; Biogenic Polyamines - biosynthesis; Biogenic Polyamines - metabolism; Biological and medical sciences; Chromatography, DEAE-Cellulose; Enzyme Activation - drug effects; Enzymes; Fundamental and applied biological sciences. Psychology; Glycine - chemistry; Glycine - metabolism; Glycine max; Glycine max - enzymology; Guanidinoacetic acid; Kinetics; Leguminosae; Metabolism; Molecular Weight; Plant physiology and development; Polyamine; Sorbitol - pharmacology; Soybean; Spectrometry, Mass, Electrospray Ionization; Substrate Specificity
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/S0031-9422(02)00401-6

Three-day-old soybean ( Glycine max) seedlings were exposed to 0.4 M sorbitol solution for 4 h to induce amidinotransferase activity, with the corresponding enzyme being purified to homogeneity by chromatographic separation on DEAE-Sephacel, Sephacryl S-300 and l-arginine Sepharose 4B. The purified enzyme used l-arginine and l-glycine as the major donor/acceptor of the amidino group, respectively, with formation of guanidinoacetic acid and ornithine products being confirmed by ESI-MS. The enzyme is a tetrameric protein having a molecular mass of 240,000 Da, whose thiol group is needed for enzymatic activity. The K Ms for arginine and glycine were 3.8 and 0.89 mM, respectively, with optimal temperature and pH being 37 °C and 9.5, respectively. The soybean amidinotransferase could be indirectly involved in nitrogen metabolism, as suggested by the observation that arginine:glycine amidinotransferase in soybean axes is indirectly involved in putrescine biosynthesis and displays feedback control at high levels of an endogenous regulator, putrescine. Amidinotransferase was purified from soybean ( Glycine max).