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Title: Stretches of oligogalacturonan are present in the backbone of rhamnogalacturonan I from cotton suspension culture cell walls

Conference · · Plant Physiology, Supplement; (United States)
OSTI ID:5601021
;  [1]
  1. Oklahoma State Univ., Stillwater (United States)

A polysaccharide fraction, solubilized from cotton suspension culture cell walls by sequential treatments by endopolygalacturonase and cellulase and purified by gel filtration chromatography, contained the sugars characteristic of rhamnogalacturonan I (RGI). A known structural feature of the backbone of RGI is the repeating disaccharide galA-rha; however, the ratio of galA to rha residues was found to be 1 {center dot} 9:1. Treatment of the RGI preparation with liquid HF (containing 1% water) at {minus}23{degree} caused cleavage of most of the rhamnosyl linkages without cleavage of galacturonosyl linkages. Neutral sugar linkages of the sidechains were also mostly cleaved. Characterization of the products from the backbone by nmr spectroscopy, compositional analysis, and liquid secondary ion mass spectrometry suggested that the backbone of the RGI is made up of short segments ({approximately} 10 units) of the galA-rha repeat interspersed with short homogalacturonan segments of {approximately} 10 galA residues of which about 40% are methyl esterified. The sequential enzyme treatments only solubilize {approximately} 40% of the RGI. The residual RGI contains a higher proportion of falA-rha repeats in its backbone.

DOE Contract Number:
FG05-86ER13496
OSTI ID:
5601021
Report Number(s):
CONF-9107184-; CODEN: PPYSA
Journal Information:
Plant Physiology, Supplement; (United States), Vol. 96:1; Conference: Annual meeting of the American Society of Plant Physiology, Albuquerque, NM (United States), 28 Jul - 1 Aug 1991; ISSN 0079-2241
Country of Publication:
United States
Language:
English