The formation of oligoglucans linked to lipid during synthesis of beta-glucan by characterized membrane fractions isolated from peas.
Membrane fractions were obtained from peas roots by using a method that permitted the isolation of a fraction rich in relatively intact dictyosome stacks. No chemical fixatives were used. The method involved incubation of the roots with cellulase, followed by gentle homogenization and sucrose-density-gradient fractionation of the homogenate. The fractions were characterized by electron microscopy. All fractions were enzymically active in incorporating glucose from UDP-glucose into water-insoluble glycolipids containing both single glucose residues and glucose oligosaccharides. Some or all of the linkages of glucose to lipid were through phosphate esters. A substance containing glucose oligosaccharides attached to or very strongly adsorbed on to protein was also formed. The membrane fractions also incorporated glucose from UDP-glucose into alkali-soluble and alkali-insoluble beta-glucans, which like the oligosaccharides contained beta(1leads to 3) and beta-(1leads to4) linkages. The distribution of the enzymic activities and the chemical properties of the lipid-linked and protein-linked oligosaccharides suggest that they may be intermediates in beta-glucan synthesis. The synthetic activity is associated with smooth-membrane vesicles which may be derived from the plasma membrane.
D000681:Amylases; D000440:Butanols; D002462:Cell Membrane / Q000378:metabolism*; D002480:Cellulase; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D005947:Glucose / Q000096:biosynthesis / Q000378:metabolism; D006056:Golgi Apparatus / Q000648:ultrastructure; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D050356:Lipid Metabolism; D008928:Mitochondria / Q000378:metabolism; D009844:Oligosaccharides / Q000096:biosynthesis*; D010636:Phenols; D010944:Plants / Q000378:metabolism*; D011134:Polysaccharides / Q000096:biosynthesis*; D011402:Pronase; D012995:Solubility; D013820:Thermolysin
D000440:Butanols; D009844:Oligosaccharides; D010636:Phenols; D011134:Polysaccharides; D000681:Amylases; D002480:Cellulase; D011402:Pronase; D013820:Thermolysin; D005947:Glucose