Protein/dextran mixture

Diftis, N. and Kiosseoglou, V. (2004). Competitive adsorption between a dry-heated soy protein—Dextran mixture and surface active materials in oil-in-water emulsions. Food Hydrocolloids 18, 639-646. 

Membrane fouling characterization of protein/dextran mixtures has also been studied [29]. The first step of this work was addressed to examine the influence of fluorescent labeling on membrane fouling. Permeate fluxes of BSA/dextran... 

Kato, A., Sasaki, Y., Furuta, R., Kobayashi, K. (1990). Functional protein/polysaccharide conjugate prepared by controlled dry heating of ovalbumin/dextran mixtures. Agricultural cmdBiological Chemistry, 54, 107-112. 

The shapes of the inhibition curves in Fig. 1A, B, and E are atypical since IgA myeloma proteins are mixtures of monomers and polymers. Using a lower molecular weight dextran N-150N, rather than the higher molecular weight native B512, typical inhibition curves as shown in Fig. 1C were obtained. If the myeloma antidextran was separated into monomer and polymer portions, the usual inhibition curves could be obtained (Cisar et al., 1974). 

Sephadex. Other carbohydrate matrices such as Sephadex (based on dextran) have more uniform particle sizes. Their advantages over the celluloses include faster and more reproducible flow rates and they can be used directly without removal of fines . Sephadex, which can also be obtained in a variety of ion-exchange forms (see Table 15) consists of beads of a cross-linked dextran gel which swells in water and aqueous salt solutions. The smaller the bead size, the higher the resolution that is possible but the slower the flow rate. Typical applications of Sephadex gels are the fractionation of mixtures of polypeptides, proteins, nucleic acids, polysaccharides and for desalting solutions. 

Equilibrate a 10-ml Sephadex G-25 column with Soln. B and determine the void volume using dextran blue. Apply the reaction mixture and elute with Soln. B. Use the fractions containing the activated protein (in the case of KLH a light blue solution) immediately for conjugation (e.g.. Protocol 4.1.3). 

When a biopolymer mixture is either close to phase separation or lies in the composition space of liquid-liquid coexistence (see Figure 7.6a), the effect of thermodynamically unfavourable interactions is to induce biopolymer multilayer formation at the oil-water interface, as observed for the case of legumin + dextran (Dickinson and Semenova, 1992 Tsapkina et al, 1992). Figure 7.6b shows that there are three concentration regions describing the protein adsorption onto the emulsion droplets. The first one (Cprotein< 0.6 wt%) corresponds to incomplete saturation of the protein adsorption layer. The second concentration region (0.6 wt% < 6 proiem < 6 wt%) represents protein monolayer adsorption (T 2 mg m 2). And the third region (Cprotein > 6 wt%) relates to formation of adsorbed protein multilayers on the emulsion droplets. 

To determine what percentage of the activity released from antibody-complement-treated cells is associated with protein-containing macromolecules (e.g., lipoprotein), the supernatant from the treated cells is collected as described above, 0.7 ml of dextran sulfate and 2.0 ml of the MgClj are added to the supernatant, and the mixture is centrifuged at 4° for 15 min at 5000 g. Depending upon the lipid content of the macromolecules released from the cells, the j8-lipoprotein-dextran sulfate insoluble complexes thus formed may either float or pellet. The results in Table II... 

---