Nanostructural modification of a model homogalacturonan with a novel pectin methylesterase: Effects of pH on nanostructure, enzyme mode of action and substrate functionality

Ultrasonic Modification of Selected Polysaccharides-Review

“…So far Ultrasound has been applied in modification of several carbohydrate polymers including dextran, starch and chitosan [49], hydroxyl propyl methyl cellulose [50], carboxyl methyl cellulose, high methoxyl pectin [51], Guar gum and carrageenan gum [52,53]. While enzyme modification involves using different enzymes to break down specific bonds present in a polymer eg in pectin modification polygalacturonases are needed to depolymerize the Homogalacturonan chain, methylesterases are needed for demethylation and other enzymes to break specific bonds [54][55][56][57] similarly chemical method use specific chemicals which attack chemical bonds present in a polymer causing depolymerization [58]. These methods are laborious, expensive; require many cleaning steps and sometimes inefficient [59].…”

Pectin homogalacturonans: Nanostructural characterization of methylesterified domains

“…The structural features most often discussed in relation to its in vivo functionality are also those frequently listed as the basis for its technological and economical attributes, which focus on its ability to crosslink with divalent cations to alter the texture of foods and the rheology of water (Axelos, Lefebvre, Qiu, & Rao, 1991;Kim et al, 2013;Kim et al, 2014;Luzio & Cameron, 2007;Ngou emazong, Nkemamin, et al, 2012;Ross et al, 2011;Van Buggenhout, Sila, Duvetter, Van Loey, & Hendrickx, 2009;Van Buren, 1979;Vincent, Mansel, Kramer, Kroy, & Williams, 2013) and to stabilize acidified milk drinks (Jensen, Rolin, & Ipsen, 2010;Tromp, de Kruif, van Eijk, & Rolin, 2004). Pectin's functionality is mostly related to its net charge and the distribution of charge along the largely linear homogalacturonan (HG) regions of the molecules.…”

“…Pectin's functionality is mostly related to its net charge and the distribution of charge along the largely linear homogalacturonan (HG) regions of the molecules. The structural complexity of pectin is well established (Caffall & Mohnen, 2009;Coenen, Bakx, Verhoef, Schols, & Voragen, 2007;Ridley, O'Neill, & Mohnen, 2001;Willats, Knox, & Mikkelsen, 2006) and necessitates a statistical approach for describing a population of pectin molecules and its two major regions, i.e., homogalacturonan and rhamnogalacturonan I (Cameron, Luzio, Goodner, & Williams, 2008;Cameron, Luzio, Vasu, Savary, & Williams, 2011;Daas, Voragen, & Schols, 2001;Guillotin et al, 2005;Kim et al, 2013;Kim et al, 2014;Ralet et al, 2012;Remoroza, Buchholt, Gruppen, & Schols, 2014;Williams, Cucheval, Nasseri, & Ralet, 2010).…”

“…Of the 66 Arabidopsis PMEs included 73% were alkaline, 23% acidic and 4% neutral. Modes of action for several plant PMEs with alkaline pIs and one with an acidic pI have been studied (Cameron et al, 2008;Cameron et al, 2011;Catoire, Pierron, Morvan, Herve du Penhoat, & Goldberg, 1998;Denes, Baron, Renard, Pean, & Drilleau, 2000;Duvetter et al, 2006;Kim, Teng, & Wicker, 2005;Kim et al, 2013;Kim et al, 2014). These enzymes have been shown to remove methyl esters in a progressive fashion, producing blocks of contiguous non methylesterified GalAs and an ordered distribution of charge, at least at neutral reaction pHs and after a minimum number of contiguous GalAs have been demethylesterified.…”

“…Because of its functional importance more attention has been focused on characterizing the charged, non methylesterified domains (NMD) of the HG region and the enzyme mode of action that produces it rather than on the neutral, methylesterified domains (Cameron et al, 2008;Cameron et al, 2011;Catoire et al, 1998;Denes et al, 2000;Duvetter et al, 2006;Kim et al, 2005;Kim et al, 2013;Kim et al, 2014;Limberg et al, 2000). Characterization of the charge distribution in a population of heterogenous pectin molecules has been carried out by NMR (Catoire et al, 1998;Grasdalen, Andersen, & Larsen, 1996;Kim et al, 2005), capillary electrophoresis (Williams, Foster, & Schols, 2003) and enzyme mediated methodologies (Cameron et al, 2008;Daas, MeyerHansen, Schols, De Ruiter, & Voragen, 1999;Daas et al, 2001;Kim et al, 2013;Ralet et al, 2012).…”