Patterns of methyl and O-acetyl esterification in spinach pectins: new complexity.
Driselase-digestion of cell walls from suspension-cultures of spinach (Spinacia oleracea L.), followed by anion-exchange chromatography, gel-permeation chromatography, preparative paper chromatography and preparative paper electrophoresis, yielded ten uronic acid-containing products in addition to free galacturonic acid (GalA). These included 4-O-methylglucuronic acid, alpha-L-rhamnopyranosyl-(1-->4)-D-glucuronic acid and several oligosaccharides containing GalA residues. The structures were unambiguously determined by a combination of 1- and 2-dimensional NMR spectroscopic techniques. Five of the six homogalacturonan-derived oligosaccharides purified contained 3-O-acetyl-GalA residues; however, methyl-esterified GalA residues occurred adjacent to both 2-O-acetyl-GalA and 3-O-acetyl-GalA residues. An acetylated, rhamnogalacturonan-I-derived oligosaccharide that was purified also contained 3-O-acetyl-GalA residues. Taken together with published data, our findings indicate considerable diversity in the patterns of pectin esterification. The implications for the action of pectin esterases are discussed.
Perrone
Paola
P
The Edinburgh Cell Wall Group, Institute of Cell and Molecular Biology, The University of Edinburgh, UK.
Hewage
Chandralal M
CM
Thomson
Adam R
AR
Bailey
Kevin
K
Sadler
Ian H
IH
Fry
Stephen C
SC
D002473:Cell Wall / Q000737:chemistry; D002845:Chromatography; D004951:Esterification; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D009844:Oligosaccharides / Q000032:analysis / Q000737:chemistry; D010368:Pectins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D018724:Spinacia oleracea / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*
D009844:Oligosaccharides; D010368:Pectins