Биологические науки/ 8.Физиология человека и животных

Peklo G.O., Lych I.V.

National university of food technologies, Ukraine

Immunomodulatory properties of the products of proteolysis of casein

Immunomodulatory properties of individual casein peptides origin of considerable theoretical and practical interest. These peptides were isolated from different fractions of casein. In particular, it was found that peptide hydrolysates αS1-casein affect the function of the immune system [1]. It was found that both pancreatic and trypsіn casein hydrolysates αS1-significantly inhibit the proliferation of spleen lymphocytes of mice and rabbits peyerovyh plaques, whereas peptide preparations obtained using pepsin and chymotrypsin had no effect on their introduction in vitro in cell culture, division which was stimulated by mitogens [2]. It was later discovered that the peptides obtained in the process of proteolysis αS1-casein pepsin and trypsin, significantly inhibited the proliferation of human peripheral blood mononukleotsytiv in vitro, induced mitogen [3].

For the actions chymosin is formed immune stimulating peptide called izratsydyn that matches the N-terminal amino acid sequence 1 – 23 αS1-casein. This peptide increases the resistance of mice to infection caused Staphilococcus aureus. In addition, izratsydyn for intravenous administration to mice stimulated phagocytic response in vivo in an infection caused by Candida albicans. It was also shown that the introduction of izratsydynu udder prevents the development of mastitis in cows. Fragments 90 – 95 and 90 – 96 αS1-casein opiate inherent properties, and a number of fee-based peptides, including β-endorphin, exhibit immunomodulatory properties in vitro and in vivo, in particular enhance the proliferative response, increase the activity of natural killer cells and neutrophil locomotion [4].

Depending on the concentration of β-kazomorfyn-7 (fragment 60 – 66 β-casein) and β-kazokinin 10 (fragment 193 – 202 β-casein) can have opposite effects on proliferation Modulator peripheral blood lymphocytes person. In particular, both peptides at low concentrations exhibit inhibitory effect on the proliferation mitogen stimulated culture of T-lymphocytes in vitro, but in high concentrations, on the contrary, increase cell proliferation of culture [3]. For β-kazokininiv – peptides that inhibit the activity of angiotensin-converting enzyme characterized by the ability to stimulate phagocytosis collected by peritoneal macrophages of mice and prevent the development of infections caused by Klebsiella pneumoniae, after intravenous injection of mice at doses less than 0.5 mg/kg [ 5]. In addition, β-casein peptides as inhibitors APE affect the regulation of the activity of the immune system by preventing the breakdown of bradykinin.

Fragment of tripsin Feng Feng – Ser – Asp – Liz (residue 17 – 21 κ-casein) and bovine para-κ-casein (sequence 1 – 105 κ-casein) tend to enhance the formation of antibodies and increase the activity of human and murine macrophages in vitro [6]. Tyr – Gly (dipeptide fragment 38 – 39 κ-casein) is also characterized monomodular properties. Believe that he can pass through intestinally barrier and act on peripheral lymphocytes. In particular, it is shown monotonously the effect of this dipeptide on the proliferation of peripheral blood lymphocytes in vitro.

Antithrombotic peptides of casein origin. Among the bioactive peptides derived from milk proteins of casein complex, there are those that affect the processes of coagulation. The formation of a blood clot is important for the protection of blood loss arising from damage to blood vessels or tissue. As hemocoagulation and coagulation of milk are important physiological coagulation process. There is a great similarity between these processes. Human fibrinogen (γ-chain) has a similar primary structure of κ-casein cow or hlikomakropeptide (HMP), which it formed. In 1978 Jolles et al. [7] suggested that γ-chain of fibrinogen and κ-casein arising from the common ancestor within the last 450 million. years. There are structural and functional similarities between the γ-chain C-terminal decapeptide (400 – 411), which is involved in binding to receptors on platelets and various peptides of fragment 106 – 116 κ-casein of cow, which are called “kazoplateliny” (table. 1).

Comparison of amino acid sequences of fibrinogen and peptide

with κ-casein of cow

Table. 1

Dodecapeptide γ-chain fibrinogen	400H-H-L-G-G-A-K-Q-A-G-D-V411
Undecapeptide κ-casein	106M-A-I-P-P-K-K-N-Q-D-K116
γ-chain of fibrinogen	169I-K-P-L-K-K-A-N-Q-Q-F177

The process of splitting of fibrinogen thrombin and cleavage κ-casein enzyme, that capable of clotting milk chymosin also have some similarities. As blood clotting and coagulation of milk defined processes limited proteolysis; thrombin cleaves two – Arg – Hli residues, resulting in the formation of fibrin and fibrinpeptide and chymosin splits unique relationship Feng Matt, forming pair-κ-casein and GMP. Short soluble peptides (fibrinopeptides and kaskopeptides) are formed in both processes of blood clotting and milk, respectively. As fibryno- and kazohlikopeptydy have different amino acid sequence but are inherent in the overall negative charge, and neither of peptides contains cysteine residues or tryptophan. ε-amino groups of lysine, possibly involved in processes as aggregation of fibrin and casein. Calcium also plays an important role in the second phase of coagulation of milk and in the aggregation of fibrin monomers. Prosthetic group formed by residues sugars do not play a significant role in the processes of coagulation, but inhibit the activity of chymosin or thrombin. κ-Casein inhibits thrombin-induced aggregation and secretion thrombin-induced serotonin in vitro, reaching 50% inhibition at a concentration of 10 μM [8]. Unlike κ-casein, a pair-κ-casein did not show any activity. GMF (106-116) inhibits both thrombin and ADP-induced platelet aggregation, causing 50% – do not brake at a concentration of 10 μM and 250 μM, respectively.

Summarizing the data, it should be noted that the phenomenon of formation of biologically active peptides during proteolysis of caseins not only expands our understanding of the biological value protein milk, but also the concept of biological value protein food. It can also contribute to a better understanding of the complex structure and heterogeneity caseins, which apart from having the body needs amino acids perform important protective and regulatory functions.

The formation of bioactive peptides from caseins is for action on casein proteolytic enzymes lactic acid bacteria and proteases that are capable of clotting milk This proves that the bioactive casein peptides formed in fermented dairy products, which can be an important part of their biological value.

Biologically active peptides casein new origin may be used in the treatment and prevention of diseases in humans. For this purpose, they can get through organic synthesis and use as dietary supplements. Another way might be the selection of strains of lactic acid bacteria that are capable in the production of fermented dairy products break down casein to form bioactive peptides specific [9]. Today dairy products with antihypertensive properties produced in Japan (“Kalpis”), Finland (“Evolyu”). Their antihypertensive properties are due to the formation of two tripeptides (VPP/IPP) of β-casein by the action of proteolytic enzymes L. helveticus. Also seems promising bioactive peptides obtaining drugs as a result of specific proteolysis of casein or total factions and used in dietary and functional food. In the Netherlands and of Denmark has made some ingredients that contain biologically active fosfopeptydy (“Kapolak”, Denmark), angiotensin-converting enzyme (“TensVida”, Netherlands) [10,11]. In Ukraine, conducting research through the formation of bioactive peptides from casein origin antihypertensive effect, but products which have been used casein bioactive peptides have been developed.

Literature

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2. Otani H., Hata I. Inhibition of proliferative responses of mouse spleen lymphocytes and rabbit Peyer’s patch cells by bovine milk caseins and their digests // J. Dairy Res. — 1995. — V. 62. — P. 339–348.

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4. Elitsur Y., Luk G. D. Betacasomorphin (BCM) and human colonic lamina propria lymphocite proliferation // Clin. Experim. Immun. — 1991. — V. 85. — P. 493–497.

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6. Sutas Y., Hurme M., Isolauri E. Down-regulation of anti-CD3 antibody_induced IL-4 production by bovine hydrolyzed with Lactobacillus casei GG-derived enzymes // Scand. J. Immun. — 1996. — V. 43. — P. 687–689.

7. Jolles P., Loucheux-Lefebvre M. H., Hen) schen A. Structural relatedness of κ-casein and fibrinogen γ-chain // J. Molec. Evol. — 1978. — V. 11. — P. 271–277.

8. Rutherfurd K. J., Gill H. S. Peptides affecting coagulation // Brit. J. Nutr. — 2000. — V. 84, Suppl. 1. — S. 99–102.

9. Algaron F., Miranda G., Le Bars D., Monnet V. Milk fermentation by Lactococcus lactis with modified proteolytic systems to accumulate potentially bioactive peptides // Ibid. — 2004. — V. 84. — P. 115–123..

10. Corredig M. Dairy_derived ingredients: food and nutraceutical uses. — USA: CRC Press, 2010. — 690 p.

11. Chandan R. C., Kilar a А. Dairy ingredients for food processing. — USA: Wiley-Blackwell, 2011. — 522 p.