STUDIES ON APPLE PROTOPECTIN .3. CHARACTERIZATION OF THE MATERIAL EXTRACTED BY PURE POLYSACCHARIDASES FROM APPLE CELL-WALLS

Plant cell walls contain polymers with complex and badly understood interactions that can be studied by enzymic extraction. Apple cell wall material, partially depectinated by a chelating agent, was treated with pure polysaccharidases (pectin-lyase, polygalacturonase, pectinesterase, endo-beta-(1,4)-glucanases, exo-beta-(1,4)-glucanase, endo-alpha-(1,5)-arabinase, arabinofuranosidase, endo-beta-(1,4)-galactanase and endo-beta-(1,4)-xylanase) and combinations of these enzymes. Glucanases, arabinanases and galactanase extracted neutral oligomers. Enzyme formulations active on highly methylated pectins freed galacturonate oligomers and high-molecular-weight material. Addition of endo-beta-(1,4)-glucanase to these enzyme formulations increased the amounts of high-molecular-weight material in the extracts. One of the endo-beta-(1,4)-glucanases had a more marked action. The high-molecular-weight material was rich in neutral sugars, notably arabinose and galactose, and was degraded to a large extent by arabinanases and galactanase. The results were analysed by principal component analysis.