Purification and characterization of biologically active 1,4-linked α-d-oligogalacturonides after partial digestion of polygalacturonic acid with endopolygalacturonase
✍ Scribed by Mark D. Spiro; Keith A. Kates; Alan L. Koller; Malcolm A. O'Neill; Peter Albersheim; Alan G. Darvill
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 971 KB
- Volume
- 247
- Category
- Article
- ISSN
- 0008-6215
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✦ Synopsis
A procedure is described for generating and puking biological~ active (1 + 4 jlinked cu-n-oligogalacturonides (oligogalac~ronides).
Oligo~alacturonides are generated by treatment of ~lygalacturonic acid (PGA) with a homogeneous fungal n-(1 -+ 4jendopolygalacturonase (EPG). Oligogalacturonides with a dp greater than seven were selectively precipitated in the presence of sodium acetate and ethanol. Oligogalacturonides with a dp less than 11 and modified oligogalacturonides remained soluble. Oligogalacturonides with a dp between 10 and 15 were purified from the resolubilized NaOAcethanol-precipitated material using Q-Sepharose fast-flow anion-exchange chromatography followed by semipreparative high performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). Approximately 70 mg of each homogeneous oligogalacturonide (dp between 10 and 15) was obtained from 10 g of EPG-treated PGA. The tridecagalacturonide fraction was selected for chemical and structural characterization and was shown to be homogeneous by glycosyl-residue composition analysis, HPAEC-PAD, FABMS, and 'H NMR spectroscopy. The purified tridecagalacturonide elicited phytoalexin accumulation in soybeans and induced flower formation and inhibited root formation in tobacco thin-cetl-layer explants. * In this paper, the term "oligogalacturonides" is used to describe oligosaccharides composed exclusively of (1 + Qlinked a-o-galactosyluronic acid residues.