Compositions – Preservative agents – Anti-corrosion
Patent
1990-05-04
1994-07-19
Stoll, Robert L.
Compositions
Preservative agents
Anti-corrosion
252308, 252312, 252356, 426602, B01J 1300, B01F 1730
Patent
active
053306821
DESCRIPTION:
BRIEF SUMMARY
SUMMARY
This invention concerns the structure and use of peptide emulsifiers in such industrial products as foods, cosmetics, and pharmaceuticals.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1, 3, 5, 7, 9, 11, 13, 15 and 17 are helical wheel representations of the structure of peptides 1, 2, 3, 4, 5, 6, 7, 8 and 9 respectively.
FIGS. 2, 4, 6, 8, 10, 12, 14, 16, and 18 are helical net representations of the structure of peptides 1, 2, 3, 4, 5, 6, 7, 8 and 9 respectively.
FIG. 19 is a graph of emulsifying activity and helical structure against peptide length.
DESCRIPTION OF THE INVENTION
This invention relates to emulsifiers.
Colloids are dispersions of particles of an immiscible substance in a liquid. An emulsion is a dispersion of one immiscible liquid in another, a foam is a dispersion of gas bubbles in a liquid, and a suspension is a dispersion of solid particles in a liquid. Colloids are thermodynamically unstable, because of their high interfacial energy. If a suitable pathway is available to them they will separate into two discrete phases with the minimum possible interfacial area between them. An emulsifier is a substance which acts at the interface between the two phases in a colloid. Such a molecule is amphipathic, which means that separate parts of its structure have affinities for each of the two phases, even though the phases do not have any affinity for each other. Consequently it occupies the interface and lowers the interfacial energy, so that less work has to be done to create a colloidal dispersion from two separate phases than if the emulsifier was absent. An effective emulsifier also forms a film at the interface, the structural integrity of which has to be disrupted for the phases to separate again. Thus, although the colloid remains thermodynamically unstable it is stabilized by kinetic constraints on breakage.
Emulsifiers are frequently used in food preparation. Most such emulsifiers are lipid derivatives such as fatty acid esters. Emulsifiers such as these are excellent at aiding emulsion formation, but do not form strong interfacial films. Consequently they are often used in conjunction with stabilizers, which increase the viscosity; of the continuous phase, thus immobilizing the particles which comprise the dispersed phase, and preventing them from coalescing.
Almost all proteins are surface active to some extent, and so they too are used as emulsifiers in food products (see Pearce & Kinsella, J. Agric. Food Chem., 26(3), 716-723, 1978), However, few if any proteins have evolved specifically to become an emulsifier, and only a few proteins have natural functions which are in any way related to emulsification, for example caseins and lipoproteins.
All proteins are surface active to some extent, and this activity can usually be enhanced if they are partially denatured (e.g. by mechanical treatment or heating), so that their amphipathic structural elements are exposed to interact with an interface and with other protein molecules. The possible role of alpha helices, having hydrophilic and hydrophobic faces, in lipid-polar interfaces has been disclosed (see, for example, the respective papers by Kaiser et al, Sparrow et al and Epand et al in "Peptides: Structure and Function", Proc. Am. Peptide symp. 9, 1985) but largely in the case of receptor-ligand interactions. No one has previously proposed using substantially isolated alpha helices as emulsifiers.
One aspect of the present invention provides an emulsifier comprising a polypeptide consisting substantially of at least one region which is capable of forming an alpha-helix having hydrophilic and hydrophobic axial domains such that the said region of the polypeptide may lie on a fat/water interface with the hydrophilic domain in the water phase and the hydrophobic domain in the fat phase, the said alpha-helix having at least 2 turns.
By "consisting substantially" of alpha helix, we mean that the polypeptide has at least a majority of amino acid residues which are of such a nature and which are so arranged that they will tend to for
REFERENCES:
patent: 4943527 (1990-07-01), Protter et al.
patent: 5135736 (1992-08-01), Anderson et al.
P. Dunnill, Biophysical J. 8:865-875 (1968).
E. T. Kaiser and F. J. Kezdy, Science 223:249-255 (1984).
Stephen J. Kennedy, J. Memb. Biol. 42:265-279 (1978).
Kevin N. Pearce and John E. Kinsella, J. Agric. Food Chem. 26:716-723 (1978).
Stephen W. Provencher and Jurgen Glockner, Biochemistry 20:33-37 (1981).
Stephen W. Provencher, Computer Physics Communications 27:229-242 (1982).
E. Kaiser et al., Short Communication Anal. Biochem. 34: 595-598 (1970).
Harpers Review of Biochemistry, 20th Ed. p. 35.
J. T. Sparrow et al., Proc. Amer. Peptide Symp. Proc. 9, Peptides and Function, 1987, pp. 865-874.
Chem. Abstracts vol. 167, 1987 E. Dickinson Abst. No. 31418d.
R. M. Epand et al. Proc. Amer. Peptide Symp., Proc. 9, Peptides Structue and Function 1987, pp. 875-878.
Segrest et al., "A Theory of Lipid-Protein Interactions in the Plasma Lipoproteins", FEBS Letters, vol. 38, No. 3, pp. 247-253 (1974).
M. Schiffer et al., "Use of helical wheels to represent the structures of proteins and to identify segments with helical potential," Biophysical Journal, vol. 7, 1967.
E. T. Kaiser et al., "The Design and Construction of Peptides and Proteins with Amphiphilic Secondary Sturctures," Proceedings of The Amer. Peptide Symposium Proc. 9, Peptides Structure and Function, 1987, pp. 855-864.
Chem. Abstract, vol. 106, 1987 E. Dickenson, "Mixed Protein aceous emulsifiers: review of competitive protein absorbtion and the relationship to food colloid stabilization".
Brock Christopher J.
Enser Michael B.
Agricultural & Food Research Council
Matzmaier Daniel S.
Stoll Robert L.
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