Glycomacropeptide (GMP) is a highly bioactive whey protein with superior purity. Davisco Foods International, Inc. has developed a unique process by which a purified form of glycomacropeptide is isolated from the whey after cheesemaking. The result is a light colored, mild tasting, free flowing powder ideal for usage in both functional foods and beverages, and dietary supplements.
GMP is a casein-derived whey peptide. When milk is treated with chymosin during cheesemaking, the milk protein (k-casein) is hydrolyzed into two peptides. The larger peptide containing the amino acid residues 1-105 is called para-k-casein, which becomes part of the cheese curd, while the smaller peptide containing amino acid residues 106-169 becomes soluble and part of the whey. The peptide is relatively small, with a molecular weight of 8000 Daltons, however due to glycosylation its actual size can range from 25000 to 30000 Daltons. There are two major variants of GMP, variant A and variant B, which differ in two amino acids. Different abbreviations are used to identify GMP, but all refer to the same molecule found in whey. CMP is the abbreviation for caseinmacropeptide, cGMP is used as a more descriptive designation of casein-glycomacropeptide. It is sometimes also referred to as CDP (casein-derived peptide) or CGP (caseinglycopeptide) to identify its origin.
GMP and Sialic Acid
GMP has many unique characteristics compared to other whey proteins. The “glyco” portion of its name refers to the saccharide groups that are attached to the peptide backbone of the molecule. Researchers have identified five different heterogeneous sugar chains related to GMP derived from mature bovine milk. The most prominent of these is N-acetylneuraminic acid, commonly known as sialic acid. The glycolysation or the amount of sialic acid of GMP varies widely and is affected by the manufacturing process. Davisco’s GMP has a high level of purity and contains approximately 8.5% sialic acid on a GMP basis.
GMP and Amino Acids
GMP differs from other whey proteins in its amino acid profile. The uniqueness of GMP is the low levels of aromatic amino acids (phenylalanine, tryptophan, and tyrosine). GMP also has relatively high amounts of branched chain amino acids (isoleucine and valine). The combination of low aromatic amino acids and high BCAAs allows GMP to be an ideal ingredient in nutritional formulations for people suffering from hepatic diseases. The low level of phenylalanine in Davisco’s GMP also makes it a highly desirable nitrogen source in the special diets formulated for phenylketoneuria patients.
PKU
Phenylketonuria, or PKU is a rare, hereditary, metabolic disorder. PKU is inherited as an autosomal recessive trait. In the United States, about one in every 19,000 births inherit this metabolic abnormality.
For a person with normal metabolism, phenylalanine is an essential amino acid that must be provided in the diet. However, in a phenylketonuric, dietary phenylalanine cannot be metabolized in a normal fashion because of a missing enzyme. As a result, a person with PKU consuming a normal diet would accumulate high levels of phenylalanine and its derivatives, causing the toxicity to the central nervous system and possible brain damage. Special low-phenylalanine diets that provide adequate protein are essential for phenylketonurics. Davisco’s purified GMP is an ideal ingredient in such diets since it contributes a minimal amount of phenylalanine.
| Amino Acid Profile – Davisco’s GMP | |
Amino Acid |
Grams per 100g protein |
Alanine |
5.5 |
Arginine |
0.5 |
Aspartic Acid |
8.6 |
Cysteine |
0.1 |
Glutamic Acid |
20.5 |
Glycine |
1.1 |
Histidine* |
0.3 |
Isoleucine*† |
10.1 |
Leucine*† |
2.6 |
Lysine* |
5.9 |
Methionine* |
1.8 |
Phenylalanine* |
0.5 |
Proline |
12.5 |
Serine |
6.1 |
Threonine* |
15.8 |
Tryptophan |
0.0 |
Tyrosine* |
0.1 |
Valine*† |
8.0 |
* Essential Amino Acid |
|
Dental Caries and Plaque Reduction
Plaque and dental caries are a result of microbial adhesion and activity on the dental surface. GMP has been shown to have a protective effect by reducing the binding of bacteria, such as the Streptococcus species,on a saliva-covered tooth model and the inner lining of the cheek. Scientists believe that by inhibiting the cariogenic bacteria, GMP reduces dental plaque and caries.1,2,3
Infant Formulations
Bifidobacteria inhibit growth of pathogenic bacteria in the GI tract and are important for the protection of infants from gastrointestinal diseases. Although many factors contribute to the colonization and growth of bifidobacteria, various studies seem to indicate the GMP may promote the growth of these beneficial organisms.8,9 Additional evidence demonstrates that GMP has immuno-modulatory effects and affords a passive defense mechanism to newborns.4,5
References
1Aimutis, W. R. 2004. Bioactive Properties of Milk Proteins with Particular Focus on Anticariogenesis. Journal of Nutrition 134: 989S-95S.
2Janer, C., J. Díaz, C. Peláez, and T. Requena. 2004. The Effect of Caseinomacropeptide and Whey Protein Concentrate on Streptococcus Mutans Adhesion to Polystyrene Surfaces and Cell Aggregation. Journal of Food Quality 27: 233-8.
3Neeser, J. R., A. Chambaz, S. Del Vedovo, M. J. Prigent, and B. Guggenheim. 1988. Specific and Nonspecific Inhibition of Adhesion of Oral Actinomyces and Streptococci to Erythrocytes and Polystyrene by Caseinoglycopeptide Derivatives. Infection and Immunity 56(12): 3201-8.
4Azuma, N., K. Yamauchi, and T. Mitsuoka. 1984. Bifidus Growth-Promoting Activity of a Glycomacropeptide Derived From Human K-Casein. Agricultural and Biological Chemistry 48(8): 2159-62.
5Bezkorovainy, A., D. Grohlich, and J. H. Nichols. 1979. Isolation of a Glycopolypeptide Fraction with Lactobacillus Bifidus Subspecies Pennsylvanicius Growth-Promoting Activity From Whole Human Milk Casein. American Journal of Clinical Nutrition 32: 1428-32.
