Evidence for a blockwise distribution of acetyl groups onto homogalacturonans from a commercial sugar beet (Beta vulgaris) pectin.
Commercial acid-extracted sugar beet pectin was extensively hydrolysed using an endo-polygalacturonase (AnPGI from Aspergillus niger or AnPGII from A. niger or FmPG from Fusarium moniliforme) in combination with Aspergillus aculeatus pectin methyl-esterase (AaPME). The homogalacturonan-derived oligogalacturonates released were quantified by high-performance anion-exchange chromatography and their structure determined by mass spectrometry. The different endo-polygalacturonases exhibited variable tolerance towards acetyl groups. AnPGI was the most active and FmPG the less. A hypothetical homogalacturonan was constructed using the AnPGI-recovered oligogalacturonates as building blocks and the validity of the model was checked taking into account FmPG observed requirements and hydrolysis products. A blockwise repartition of the acetyl groups onto sugar beet pectin homogalacturonan is proposed.
Ralet
Marie-Christine
MC
INRA, UR1268 Biopolymères Interactions Assemblage, Rue de la Géraudière, B.P. 71627, F-44300 Nantes, France. ralet@nantes.inra.fr
Crépeau
Marie-Jeanne
MJ
Bonnin
Estelle
E
D000107:Acetylation; D027461:Beta vulgaris / Q000737:chemistry*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002852:Chromatography, Ion Exchange; D005690:Galactose / Q000737:chemistry*; D006868:Hydrolysis; D008745:Methylation; D010368:Pectins / Q000737:chemistry*
D010368:Pectins; D005690:Galactose