Rhamnogalacturonan I in Solanum tuberosum tubers contains complex arabinogalactan structures
- 作者：Ø ; bro ; Jens ; Harholt ; Jesper ; Scheller ; Henrik Vibe ; Orfila ; Caroline
- 关键词：Solanum tuberosum ; Solanaceae ; Potato ; Pectin ; Rhamnogalacturonan I ; Endo-galactanase ; Endo-arabinanase ; Aspergillus niger ; ELISA ; HPAEC-PAD
- 刊名：Phytochemistry
- 出版年：2004
- 期刊代码：85_00319422
- 类别：ch
- 出版时间：May, 2004
- 卷：65
- 期：10
- 页码：1429-1438
- 文件大小：268 K
摘要
A rhamnogalacturonan I polysaccharide was isolated from potato (Solanum tuberosum cv. Posmo) tuber cell walls and characterised by enzymatic digestion with an endo-β-1→4-galactanase and an endo-^5;-1→5-arabinanase, individually or in combination. The reaction products were separated using size-exclusion chromatography and further analysed for monosaccharide composition and presence of epitopes using the LM5 anti-β-1→4-galactan and LM6 anti-^5;-1→5-arabinan monoclonal antibodies. The analyses point to distinct structural features of potato tuber rhamnogalacturonan I, such as the abundance of β-1→4-galactan side chains that are poorly substituted with short arabinose-containing side chains, the presence of ^5;-1→5-arabinan side chains substituted with β-1→4-galactan oligomers (degree of polymerisation >4), and the presence of ^5;-1→5-arabinans that resist enzymatic degradation. A synergy between the enzymes was observed towards the degradation of arabinans but not towards the degradation of galactans. The effect of the enzymes on isolated RG I is discussed in relation to documented effects of enzymes heterologously expressed in potato tubers. In addition, a novel and rapid method for the determination of the monosaccharide and uronic acid composition of cell wall polysaccharides using high-performance anion exchange chromatography with pulsed amperometric detection is described.