• Food Science of Animal Resources
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• v.44 no.2
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• pp.299-308
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• 2024

Proteins in whey have prebiotic and antimicrobial properties. Whey protein comprises numerous bioactive proteins and peptides, including glycomacropeptide (GMP), a hydrophilic casein peptide that separates with the whey fraction during cheese making. GMP has traditionally been used as a protein source for individuals with phenylketonuria and also has prebiotic (supporting the growth of Bifidobacterium and lactic acid bacteria) and antimicrobial activities. GMP supplementation may help positively modulate the gut microbiome, help treat dysbiosis-related gastrointestinal disorders and improve overall health in consumers.

• Journal of agriculture & life science
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• v.43 no.1
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• pp.25-33
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• 2009

This study was carried out to isolate and characterize the glycomacropeptide (GMP) prepared from cow's milk and Korean native goat's milk and to examine the effects of their tryptic hydrolysates on inhibition of platelet aggregation in an in vitro experiment. The GMP derived from Holstein, Korean native goat and Hanwoo migrated at 20 KDa. Sialic acid contents in skim milk of Holstein, Korean native goat and Hanwoo were $36.86{\pm}2.36$, $37.98{\pm}1.27$ and $31.19{\pm}1.87{\mu}g/mg$, respectively. Tyrosine was detected in both bovine and caprine GMP. The in vitro inhibition rate of platelet agregation by tryptic hydrolysates of Holstein, Korean native goat and Hanwoo GMP were 4.02, 5.51 and 12.77%, respectively at reaction time 30 seconds. The inhibition of platelet aggregation by tryptic hydrolysates of bovine and caprine GMP are increased with increasing reaction time. The platelets staining revealed higher counts of platelets after the addition of GMP hydrolysates; however addition of ADP reduced the platelet count within 30 seconds and the platelets were not detected after 120 seconds. The results of this study indicate that tryptic hydrolysates of bovine and caprine GMP contain some small peptides with platelet aggregation inhibition properties. Further research on these lines may help prevent platelet aggregation related abnomalities in human.

• Food Science of Animal Resources
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• v.20 no.2
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• pp.159-165
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• 2000

Glycomacropeptide(GMP) was purified from cheese whey which is obtaining as a byproduct in cheese producing. Cheese whey was first concentrated 10 times with a ultrafiltration aparratus, and then heated at 95$^{\circ}C$ for 5 min. The concentrated fraction was centrifuged at 20,000$\times$g for 30 min to remove fat layer. The supernatant layer enriched GMP protein was fractionated by ion exchange chromatography on DEAE-Sepharose Fast Flow column. GMP was bound to DEAE resin and eluted with 0.1~0.25 M NaCl when using a linear NaCl gradient from 0 M to 0.5 M. The purified GMP gave a single band of 24 kDa which seems to be trimer molecular weight in SDS-PAGE, and migrated to the same molecular weight with control GMP obtained commercially. Its amino acid composition were consistent with that of standard GMP. About 0.71 g of GMP was recovered from 1 L of cheese whey. These results indicate that glycomacropeptide could be simply purified from cheese whey by using ultrafiltration and DEAE column chromatography.

• Journal of Dairy Science and Biotechnology
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• v.29 no.2
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• pp.17-23
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• 2011

The focus of this study was to clarify the relation between the nitric oxide (NO) production and cytokine expression including tumor necrosis factor-${\alpha}$ (TNF) and interleukin-6 (IL-6), and also investigated the effect of G-NANA (N-acylneuraminic acid isolates from glycomacropeptide) or S-NANA (Synthetic N-acylneuraminic acid) on LPS stimuli from RAW264.7 cell. The NANA is the predominant sialic acid found in mammalian cells and G-NANA is isolation of GMP (GMP is a valuable bioactive peptide with a varying degree of glycosylation including sialic acid). The lipopolysaccharide (LPS) of Gram-negative bacteria induces the expression of cytokines and potent inducers of inflammatory cytokines such as TNF-${\alpha}$ and IL-6. In this experiment, upon stimulation with increasing concentrations of chitosan, the LPS-stimulated TNF-${\alpha}$ and IL-6 secretion was significantly recovered with in the incubation media of RAW264.7 cells. Consistently, RT-PCR with mRNA and immunoblot analysis with anti-cytokine antiserum including TNF-${\alpha}$ and IL-6 showed that the amount of TNF-${\alpha}$ and IL-6 secretion in the incubation media recovered with the concentration of chitosan. The LPS-stimulated NO secretion was significantly recovered with in the 6 and 12 h incubation media of RAW264.7 cells, too. The recovery effect of G-NANA on IL-6 and NO secretion may be induced via the stimulus of TNF-${\alpha}$ in RAW264.7 cell. These results once again suggest that G-NANA may have the anti-inflammatory effect via the stimulus of TNF-${\alpha}$ in the LPS-stimulated inflammation in RAW264.7 cells.

• Toxicological Research
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• v.34 no.3
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• pp.259-266
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• 2018

Glycomacropeptide (GMP), a whey protein of milk, has functions including differentiation and development of nervous system, and anticancer and antiviral effects. To develop new functions, N-acetylneuraminic acid (NANA) containing 7% sialic acid was separated from GMP to produce G-7%NANA. N-glycolylneuraminic acid (Neu5Gc) is another type of sialic acid separated from GMP, which has been linked to immune disorders and chronic inflammation-mediated diseases. Therefore, safety was a concern in the use of G-7%NANA in functional foods. To ensure safety, in this study, three genetic toxicity tests on G-7%NANA were conducted. In the reverse mutation test using Salmonella typhimurium TA98, TA100, TA1535, TA1537, and Escherichia coli WP2uvrA, and in the chromosome aberration test using CHO-K1 cells, no significant differences from negative control were found at all dose levels. Similarly, no dose-related differences were evident compared to negative control in the micronucleus test using ICR mice. There was no evidence of G-7%NANA-related genetic toxicity.

• Food Science of Animal Resources
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• v.25 no.4
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• pp.478-482
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• 2005

Bovine k-casein macropeptide was prepared by adding TCA (3, 6, and $12\%$) treatment after chymosin reaction. Each TCA soluble macropeptide was fractionated into five peak by ion exchange column chromatography. In proportiion to TCA concentrations, the ratio of peak area showed different the elution pattern. At the 6 and $12\%$ TCA concentration, area ratio of P-I which did not content carbohydrates was decreased to 19.9 and $17.0\%$ of total peak area respectively. The area of P-III was changed from $10.2\%\;to\;26.2\;and\;13.2\%$ when the TCA concentration was increased from 3 to 6 and $12\%$ Cholera toxin binding activity of k-casein macropeptide eluted at $0.17\~0.18M$ NaCl gradient was not inhibited by 6 and $12\%$ TCA treatments. The use of $6\%$ TCA as extraction buffer was feasible and led to an effective separation of the peak III.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2000.11a
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• pp.87-87
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• 2000

• Nutrition Research and Practice
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• v.11 no.1
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• pp.11-16
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• 2017

BACKGROUND/OBJECTIVES: Helicobacter pylori (H. pylori) colonization of the stomach mucosa and duodenum is the major cause of acute and chronic gastroduodenal pathology in humans. Efforts to find effective anti-bacterial strategies against H. pylori for the non-antibiotic control of H. pylori infection are urgently required. In this study, we used whey to prepare glycomacropeptide (GMP), from which sialic acid (G-SA) was enzymatically isolated. We investigated the anti-bacterial effects of G-SA against H. pylori in vitro and in an H. pylori-infected murine model. MATERIALS/METHODS: The anti-bacterial activity of G-SA was measured in vitro using the macrodilution method, and interleukin-8 (IL-8) production was measured in H. pylori and AGS cell co-cultures by ELISA. For in vivo study, G-SA 5 g/kg body weight (bw)/day and H. pylori were administered to mice three times over one week. After one week, G-SA 5 g/kg bw/day alone was administered every day for one week. Tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), IL-$1{\beta}$, IL-6, and IL-10 levels were measured by ELISA to determine the anti-inflammatory effects of G-SA. In addition, real-time PCR was performed to measure the genetic expression of cytotoxin-associated gene A (cagA). RESULTS: G-SA inhibited the growth of H. pylori and suppressed IL-8 production in H. pylori and in AGS cell co-cultures in vitro. In the in vivo assay, administration of G-SA reduced levels of IL-$1{\beta}$ and IL-6 pro-inflammatory cytokines whereas IL-10 level increased. Also, G-SA suppressed the expression of cagA in the stomach of H. pylori-infected mice. CONCLUSION: G-SA possesses anti-H. pylori activity as well as an anti-H. pylori-induced gastric inflammatory effect in an experimental H. pylori-infected murine model. G-SA has potential as an alternative to antibiotics for the prevention of H. pylori infection and H. pylori-induced gastric disease prevention.

• Journal of Dairy Science and Biotechnology
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• v.34 no.2
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• pp.83-89
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• 2016

This study was designed to determine the mutagenic potential of hydrolyzed glycomacropeptide (GMP) powder (hereafter referred to as 23%-GNANA; product name: HELICOBACTROL-23) in a micronucleus test using bone marrow in ICR mice. Three experimental groups were used: a 3-step concentration group, with a maximum concentration of 2,000 mg/kg, and other sequentially two-fold lower concentrations, a negative control group, and a positive control group. The test material was administered for 2 d to observe the frequency of micronucleus formation up to 48 h after the test material was absorbed by the body. When the polychromatic erythrocyte (PCE) content of erythrocytes was compared, no significant differences were noted between the negative control group and the test group (p<0.05). Similarly, when the average numbers of micronucleated PCE (MNPCE) in 2,000 PCE per animal were compared, no significant difference was observed between the negative control group and the test group (p<0.05). No dose-response relationship with regard to the concentration of the test material administered was noted. These results allow us to conclude that hydrolyzed whey protein powder does not cause formation of micronuclei in mouse bone marrow cells under the applied conditions. In this study, the average frequency of micronucleus formation in PCE was significantly higher in the positive control group compared with the negative control group; thus, the test conditions were appropriate for detecting the frequency of micronucleus formation induced by the test material. In conclusion, the safety of 23%-GNANA test substance was verified in an in vivo micronucleus test in mice, conducted before the registration of HELICOBACTROL-23 as a food additive.

• Food Science of Animal Resources
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• v.29 no.6
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• pp.659-667
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• 2009

Casein is considered to be the main source of protein in milk; therefore, many studies have been conducted to identify casein-derived bioactive peptides and their physiological effects. Casein is inactive within the parent protein but can be liberated by various proteases and enzymatic hydrolysis during microbial fermentation and gastrointestinal digestion. Once absorbed, casein exhibits different bioavailabilities in the body. Specifically, casein-derived peptides function as angiotensin converting enzyme (ACE) inhibitor in the cardiovascular system; thus, they are expected to reduce and prevent hypertension. Additionally, casein-derived peptides behave as opioid-like peptides in the nervous system, which impacts relaxation. These peptides are also expected to modulate various aspects of immune functions. Finally, caseinophosphopeptide (CPP) and glycomacropeptide (GMP) may exhibit a number of nutritional effects such as the absorption of calcium, iron or zinc. Many studies have been conducted to evaluate casein-derived peptides due to their multifunctional properties and the results of these studies have contributed to the development of a wide variety of functional dairy products. The purpose of this paper was to review the generation of bioactive peptides, their absorption and metabolism, and their specific bioactive effects.