title: Protein- and pH-dependent binding of nascent pectin and glucuronoarabinoxylan to xyloglucan in pea.
abstract: Nascent pectin and glucuronoarabinoxylan, synthesised in vitro by membrane-bound enzymes from etiolated pea (Pisum sativum L.) epicotyls, were found to bind to pea xyloglucan in a pH-dependent manner. The binding was maximum at low pH (3-4), and decreased to almost zero at pH 6. The binding was probably non-covalent and reached saturation within 5 min. Removal of the fucose residues of xyloglucan decreased the degree of binding. Removal by protease of the proteins attached to nascent pectin and glucuronoarabinoxylan greatly reduced the maximum binding and abolished the pH-dependence. The observed binding may be of considerable significance in the process of cell-wall assembly and in the control of cell extension.
authors.affiliation: Plant Molecular Science Group, Institute of Biomedical & Life Sciences, University of Glasgow, UK.
authors.forename: S E
authors.initials: SE
authors.lastname: Rizk
authors.forename: R M
authors.initials: RM
authors.lastname: Abdel-Massih
authors.forename: E A
authors.initials: EA
authors.lastname: Baydoun
authors.forename: C T
authors.initials: CT
authors.lastname: Brett
mesh_terms: D001665:Binding Sites; D002250:Carbon Radioisotopes; D005936:Glucans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D018532:Pisum sativum / Q000378:metabolism*; D010368:Pectins / Q000378:metabolism*; D011133:Polysaccharide-Lyases / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism*; D011485:Protein Binding; D011865:Radioisotope Dilution Technique; D014574:Uronic Acids / Q000378:metabolism; D043325:Xylan Endo-1,3-beta-Xylosidase; D014990:Xylans / Q000378:metabolism*; D014995:Xylosidases / Q000378:metabolism
chemical_list: D002250:Carbon Radioisotopes; D005936:Glucans; D011134:Polysaccharides; D014574:Uronic Acids; D014990:Xylans; C114470:glucuronoarabinoxylan; C029353:xyloglucan; D010368:Pectins; D014995:Xylosidases; D043325:Xylan Endo-1,3-beta-Xylosidase; D011133:Polysaccharide-Lyases; C027349:pectin lyase