Concentration of a protein by polysaccharides

Abstract

New methods of protein concentration providing the regulation of its functional properties based on the phenomena of limited thermodynamic compatibility and complexation of proteins and polysaccharides (PS) are considered. Formation of two-phase systems for skimmed milk, clover biomass sap, and PS (pectin, arabic gum, arabinogalactan) of different kinds is studied. Establishing the phase equilibrium in all cases is accompanied by concentration of proteins and dilution of PS solution. The PS phase is as a rule, a continuous medium, and the concentrated protein phase is a dispersed phase. The first stage of the process consists in establishing the phase equilibrium. The second stage consists in phase separation. The third stage is a recovery of PS from the PS phase in the form of protein, PS complex, and recycling of PS.

Noncovalent Polymerization of Mesogens Crystallizes Lysozyme: Correlation between Nonamphiphilic Lyotropic Liquid Crystal Phase and Protein Crystal Formation

“…We believe that this thermodynamic incompatibility is due to the strong affinity for self-assembly by the nonamphiphilic mesogens. It is well-known that, when mixed in a solution, different polymers, − including proteins, − can phase separate into volumes enriched with each component. However, this phase separation does not necessarily lead to the crystallization of either component.…”

Complexation of pectins varying in overall charge with lysozyme in aqueous buffered solutions

“…Moreover, these interactions affect the physical properties of food preparations such as their clarity, stability and gel-forming ability (De Kruif & Tuinier, 2001, Tolstoguzov, 2003. The use of highly methoxylated pectins as flocculants for natural biological materials (defatted milk, milk whey, clover and alfalfa juices) allows to fractionate milk and leaf proteins (Antonov & Kiknadze, 1987) and to obtain liquid concentrates of micellar casein from defatted milk (Antonov,et al, 1982). Therefore the complexation of pectins with proteins was a subject of intense scientific interest in the last two decades (see for example Girard, Turgeon, Gauthier, 2002,2003aMaroziene, De Kruif, 2000;Zaleska, Ring, Tomasik, 2000;Sperber, Schols, Stuart, Norde, & Voragen, 2009, 2010Gilsenan, Richardson, Morris, 2003;Wang, Lee,Wang, & Huang, 2007;Ru, Wang, Lee, Ding, & Huang, 2012;Saravanan, 2010;Plashchina, Zhuravleva,& Antonov, 2007;Bayarri, Oulahal, Degraeve, & Gharsallaoui 2014;Lin et al 2015;Amara, Degraeve, Oulahal, & Gharsallaoui,2017;Schmidt, Cousin, Huchon, Boué, & Axelos, 2009).…”

Noncovalent Polymerization and Assembly in Water Promoted by Thermodynamic Incompatibility

“…When two different polymers are mixed together in a common solvent, the resulting mixture can become cloudy and eventually separate into two distinct layers . Such phase-separated systems have been widely observed in mixtures of two different biopolymers, such as proteins and polysaccharides. ,,− This phase separation is often observed for polymers; , in contrast, mixing two independently soluble small molecules often results in a homogeneous solution . For both macromolecular and small molecular systems, the spontaneity of mixing (free energy of mixing) is governed by the entropy−enthalpy balance.…”

“…5 Such phase-separated systems have been widely observed in mixtures of two different biopolymers, such as proteins and polysaccharides. 6,8,[50][51][52][53][54][55][56][57][58][59][60][61][62][63] This phase separation is often observed for polymers; 11,12 in contrast, mixing two independently soluble small molecules often results in a homogeneous solution. 8 For both macromolecular and small molecular systems, the spontaneity of mixing (free energy of mixing) is governed by the entropy-enthalpy balance.…”