Thermodynamic incompatibility of proteins

Polyakov, Vyacheslav; Grinberg, V. Ya.; Tolstoguzov, V. B.

doi:10.1016/s0268-005x(97)80024-0

Cited by 96 publications

(67 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In fact, these two proteins have been shown to exhibit incompatibility in concentrated solutions (8). However, the threshold for phase separation at the air-water interface may not be similar to that in solution owing to the fact that the thermodynamics at an interface is different from that of the bulk phase, and the conformational state of the proteins in the adsorbed state at the interface is bound to be different from that in solution.…”

Section: Discussionmentioning

confidence: 99%

“…Compatibility of two proteins in a ternary system will be dictated by a delicate interplay among the four controlling parameters, viz., protein 1-protein 2 interaction parameter (χ 12 ), protein 1-solvent and protein 2-solvent interaction parameters (χ 1s , χ 2s ), molecular weights of the two protein molecules, and conformation states of the two proteins (8). From the Flory-Huggins theory, the critical interaction parameter, χ c , for a binary mixture of polymers is 0.…”

Section: Discussionmentioning

confidence: 99%

“…Although, intuitively, two proteins in a protein 1-protein 2-water ternary system should be totally compatible when the interaction parameter χ 12 is 0, in reality they may still exhibit incompatibility in solution if there is a difference in the protein-solvent interaction parameters, |χ 1s − χ 2s |, as little as 0.03 (18). The larger the difference in |χ 1s − χ 2s | of two proteins, the greater would be incompatibility and the lower would be the threshold for phase separation in a ternary system (8). On the other hand, if the solvent is equally good for each polymer (i.e., χ 1s = χ 2s ), two polymers may yield a totally miscible solution in spite of a small positive value of χ 12 (19).…”

Section: Discussionmentioning

confidence: 99%

“…This is true of proteins as well. In concentrated aqueous solutions, mixtures of two proteins exhibit thermodynamic incompatibility of mixing and, as a result, undergo phase separation (6)(7)(8). Because the local concentration of proteins in an adsorbed protein film at the air-water interface is equivalent to 15-30%, it is likely that two-dimensional phase separation of proteins might occur in the film (5).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Incompatibility and Phase Separation in a Bovine Serum Albumin/β-Casein/Water Ternary Film at the Air–Water Interface

Sengupta

Damodaran

2000

Journal of Colloid and Interface Science

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Incompatibility and Phase Separation in a Bovine Serum Albumin/β-Casein/Water Ternary Film at the Air–Water Interface

Sengupta

Damodaran

2000

Journal of Colloid and Interface Science

View full text Add to dashboard Cite

“…1a and b. The procedure is adapted from Koningsveld and Staverman [29] and Polyakov et al [30]. The separately prepared protein and polysaccharide solutions (concentrations C o 2 and C o 3 , respectively) were mixed at 298 K in various weight ratios, yielding mixtures with protein and polysaccharide concentrations C 2 and C 3 (wt.%), respectively, which are represented on the phase diagram by the secant…”

Section: Methodsmentioning

confidence: 99%

Interfacial tension of aqueous biopolymer mixtures close to the critical point

Antonov¹,

Puyvelde²,

Moldenaers³

2004

International Journal of Biological Macromolecules

View full text Add to dashboard Cite

Proteins and polysaccharides, being the main constructional materials in many biological structures, have a limited compatibility in aqueous media. At sufficiently high concentrations, they form water-in-water emulsions. Interfacial tension is an important parameter in such systems since it is a controlling factor in the morphology development during processing. In this work a rheo-optical methodology, based on the analysis of small angle light scattering (SALS) patterns during fibril break-up, is used to study the interfacial tension of water-sodium caseinate-sodium alginate systems located close to and relatively far from the binodal. The interfacial tension close to the critical point was ∼10 −8 N/m, and it increased considerably, to a value of up to 5.2 × 10 −6 N/m farther from the critical point. For the scaling of the interfacial tension with the density difference between the phases, a scaling exponent of 3.1 ± 0.3 was found, in agreement with the critical mean-field scaling exponent of 3.

show abstract

Phase behaviour of macromolecular components in biological and food systems

Tolstoguzov¹

2000

Nahrung

View full text Add to dashboard Cite

Reasons for the greatly different phase behaviour of: (i) biological systems (cytoplasm of the cell), (ii) food systems and (iii) beverages are considered. The two phenomena: molecular mimicry and molecular symbiosis presumably control thermodynamic compatibility of biological macromolecules. The three interacting factors underlying molecular mimicry, are: (i) low excluded volume of densely packed protein globules, (ii) chemical resemblance of surfaces of the globules and (iii) the chemical information hidden in the hydrophobic interior of the globules. The symbiotic relationship presumably exists between rod-like macromolecules and protein globules, i.e. between macromolecules of the two extreme conformations typical of biopolymers. For instance, thermodynamic activity of an enzyme can be controlled by dissociation-association of rod-like macromolecules. Due to excluded volume effects, biopolymers behave as if they were in a solution of a higher concentration. Both molecular mimicry and molecular symbiosis could also be of importance for non-specific immune defence, digestion of proteins and formation of food structures. Unlike biological systems, thermodynamic incompatibility is typical of foods and still more of beverages. Denaturation, aggregation and complexing of food macromolecules decrease their mimicry and co-solubility. Due to their relatively low viscosity and high chemical and physical heterogeneity of macromolecules, the phase behaviour of beverages is similar to that of mixed solutions of synthetic polymers. Phase separation of biopolymer mixtures is of importance for controlling composition-property relationship in formulated food and drinks.

show abstract

Thermodynamic incompatibility of proteins

Cited by 96 publications

References 24 publications

Incompatibility and Phase Separation in a Bovine Serum Albumin/β-Casein/Water Ternary Film at the Air–Water Interface

Incompatibility and Phase Separation in a Bovine Serum Albumin/β-Casein/Water Ternary Film at the Air–Water Interface

Interfacial tension of aqueous biopolymer mixtures close to the critical point

Phase behaviour of macromolecular components in biological and food systems

Contact Info

Product

Resources

About