Chemistry: molecular biology and microbiology – Micro-organism – tissue cell culture or enzyme using process... – Enzymatic production of a protein or polypeptide
Patent
1992-08-31
1999-02-02
Weber, Jon P.
Chemistry: molecular biology and microbiology
Micro-organism, tissue cell culture or enzyme using process...
Enzymatic production of a protein or polypeptide
530300, C12P 2106, A61K 3800
Patent
active
058663576
DESCRIPTION:
BRIEF SUMMARY
FIELD OF INVENTION
The present invention relates to a method of obtaining limited specific hydrolysis of proteins, a protein hydrolysate obtained by the method, and a food product containing the protein hydrolysate.
BACKGROUND OF THE INVENTION
Enzymatic hydrolysis of proteins by means of proteases is a well-established method of preparing protein hydrolysates which have retained the nutritional value of the original proteins and which may therefore advantageously be used in the diet of certain patients who are unable to ingest or digest sufficient amounts of full-length proteins present in ordinary food, or which may be used to improve the nutritional value of milk substitutes for infants. Protein hydrolysates may furthermore be prepared from sources not traditionally utilized for human nutrition and may, as such, either be used as food products in themselves or as additives to other food products.
The proteases which have hitherto been used for the preparation of protein hydrolysates of this type are proteases with a broad specificity, e.g. Bacillus licheniformis alkaline protease. A major problem encountered when using proteases with a broad specificity is an often pronounced bitter taste of the protein hydrolysates produced. The bitter taste is the result of cleavage of the proteins at amino acids with hydrophobic side chains, resulting in the formation of peptides with exposed hydrophobic amino acid residues. In full-length proteins and longer peptides, the hydrophobic side chains are inaccessible due to the tertiary structure of the protein molecule in which the side chains are embedded within the folded protein. When smaller peptides are formed by proteolytic cleavage of the protein molecule, the hydrophobic side chains will become exposed and hence accessible to adjacent hydrophobic and hydrophilic receptors on the taste buds. This phenomenon has been determined to give rise to a bitter taste (cf. H. Wieser and H. -D. Belitz, Z. Lebensm. Unter.-Forsch. 159, 1975, pp. 65-72; and H. Wieser and H. -D. Belitz, Z. Lebensm. Unter.-Forsch. 160, 1976, pp. 383-392).
It has been suggested to overcome the problem of bitterness of the protein hydrolysate by limiting the degree of hydrolysis of the starting proteins, i.e. by limiting the number of peptide bonds cleaved by the protease, e.g. by monitoring the degree of hydrolysis and terminating the proteolytic reaction when a suitable degree of hydrolysis has been obtained (cf. for instance J. Adler-Nissen, Enzymic Hydrolysis of Food Proteins, Applied Science Publishers, London 1986). It has been found that such hydrolysates exhibit a reduced bitterness, at least in conjunction with other constituents of the food product in which they are included.
Another way of controlling the degree of hydrolysis is to employ specific proteases which only cleave the protein molecule at certain amino acid residues. This has been suggested by J. -M. Chobert et al., J. Agric. Food Chem. 36, 1988, pp. 220-224, reporting the use of the Staph. aureus V8 protease which hydrolyses proteins specifically at glutamic and aspartic acid residues.
SUMMARY OF THE INVENTION
It has surprisingly been found that a Bacillus licheniformis protease is specific for glutamic and aspartic acid residues and therefore capable of providing a satisfactory limited hydrolysis of proteins resulting in a protein hydrolysate which, in itself, does not have a bitter taste.
Accordingly, the present invention relates to a method of obtaining limited specific hydrolysis of proteins at Glu and/or Asp bonds, wherein an enzyme preparation comprising a proteolytic enzyme with the following characteristics: acid (Asp) residues; gram of enzyme protein; phenylmethane sulfonylfluoride; 6.5-10.0; activity, is added to a proteinaceous material followed by incubation at a neutral or weakly alkaline pH until the desired degree of hydrolysis is obtained, after which the incubation is terminated by suitably inactivating the enzyme, resulting in the formation of peptides with a C-terminal glutamic or aspartic acid residu
REFERENCES:
patent: 4100024 (1978-07-01), Adler-Nissen
patent: 4107334 (1978-08-01), Jolly
patent: 4266031 (1981-05-01), Tang et al.
patent: 5523237 (1996-06-01), Budtz et al.
Drapeau et al. (1972) "Purification and Properties of an Extracellular Protease of Staphyloccus aureus", J. Biol. Chem., 247(20), 6720-6726.
Houmard et al. (1972) "Staphylococcal Protease: A Proteolytic Enzyme Specific for Glutamoyl Bonds", Proc. Nat. Acad. Sci., USA, 69(12), 3506-3509.
Beaudet et al. (1974) "Structural Heterogeneity of the Protease Isolated from Several Strains of Staphylococcus aureus", J. Bil. Chem., 249(30), 6468-6471.
Ryden et al. (1974) "Isolation and Properties of a Staphylococcal Protease, Preferentially Cleaving Glutamoyl-Peptide Bonds", Eur J. Biochem., 44, 105-114.
Houmard (1976) "Preparation of Chromophoric Substrates for the Glutamoyl Specific Staphylococcal Protease", Int. J. Peptide Protein Res., 8, 199-204.
Mosolova et al. (1987) "Glu, Asp-Specific Proteinase from Actinomycetes", Biokhimiya, 52(3), 414-422.
Khaldarova et al. (1989) "A Glu. Asp-Specific Proteinase from Streptomyces thermovulgaris", Biokhimiya, 54(1), 32-38.
Kreier et al. (1983) "Subtilisin-Like Proteinase SSPB", Biokhimiya, 48(8), 1365-1373.
Belyaeva et al. (1980) "Comparative Study of Proteolytic Activity of Staphylococci and Identification of Specific Protease", Prikl. Biokhim. Mikrobiol., 16(6), 841-847.
Houmard et al. (1972) Proc. Nat. Acad. Sci. USA, 69(12), 3506-3509.
Mosolova et al. (1987) Biokhimiia, 52(3), 414-422.
Yoshida et al. (1988) J. Biochem., 104, 451-456.
Niidome et al. (1990) J. Biochem. , 108, 965-970.
Svendsen et al. (1992) Eur. J. Biochem., 204, 165-171.
Kakudo et al. (1992) J. Biol. Chem., 267(33), 23782-23788.
Chobert et al., J. Agric. Food Chem., vol. 36, pp. 220-224 (1988).
Wieser et al., Z. Lebensm. Unters.-Forsch., vol. 160, pp. 383-392 (1976).
Olesen, Chem. Abs., vol. 98, No. 1, p. 335, abstract No. 3693n (1982).
Budtz Peter
Dambmann Claus
Eriksen Svend
Mortensen Steen Bennike
Lambiris, Esq. Elias J.
Novo Nordisk A S
Weber Jon P.
Zelson Esq. Steve T.
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