title: Innovative enzymatic approach to resolve homogalacturonans based on their methylesterification pattern.
abstract: Three series of model homogalacturonans (HGs) covering a large range of degree of methylesterification (DM) were prepared by chemical and/or enzymatic means. Randomly demethylesterified HGs, HGs containing a few long demethylesterified galacturonic acid stretches, and HGs with numerous but short demethylesterified blocks were recovered. The analysis of the degradation products generated by the action of a purified pectin lyase allowed the definition of two new parameters, the degree of blockiness, and the absolute degree of blockiness of the highly methylesterified stretches (DBMe and DB(abs)Me, respectively). By combining this information with that obtained by the more traditional endopolygalacturonase digestion, the total proportion of degradable zones for a given DM was measured and was shown to permit a clear differentiation of the three types of HG series over a large range of DM. This double enzymatic approach will be of interest to discriminate industrial pectin samples exhibiting different functionalities and to evaluate pectin fine structure dynamics in vivo in the plant cell wall, where pectin plays a key mechanical role.
authors.affiliation: INRA, UR1268 Biopolymères Interactions Assemblages, rue de la Géraudière, BP 71627, F-44300 Nantes, France. marie-christine.ralet@nantes.inra.fr
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Ralet
authors.forename: Martin A K
authors.initials: MA
authors.lastname: Williams
authors.forename: Abrisham
authors.initials: A
authors.lastname: Tanhatan-Nasseri
authors.forename: David
authors.initials: D
authors.lastname: Ropartz
authors.forename: Bernard
authors.initials: B
authors.lastname: Quéméner
authors.forename: Estelle
authors.initials: E
authors.lastname: Bonnin
mesh_terms: D008738:Methyl Ethers / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D010368:Pectins / Q000737:chemistry / Q000378:metabolism*; D011096:Polygalacturonase / Q000737:chemistry / Q000378:metabolism*
chemical_list: D008738:Methyl Ethers; D010368:Pectins; D011096:Polygalacturonase; C003181:polygalacturonic acid