Current Data about Milk Caseins

— Cow’s milk is one of the most common triggers of food allergies in children. It is believed that the main role in the development of clinical symptoms of allergic reactions in adults is played by casein proteins, which are part of milk. To date, the main physicochemical and immunobiological properties of caseins have been studied and their primary structure has been determined. However, the question of the structural organization of the casein micelles of cow’s milk still causes much scientific controversy. Deciphering the conformational structure of caseins, the search for new IgE-binding epitopes allows us to identify ways for reducing the allergenic activity of cow’s milk caseins. The objective of this review is to summarize the available data on the structure and properties of milk casein proteins and to determine their role in the formation of sensitization to dairy products. This review describes the molecular characteristics, physicochemical properties and immunobiological functions of cow’s milk caseins, as well as the basic theoretical knowledge about the structure of the casein micelle. The primary structure of different types of caseins (αs1-, αs2-, β-, and κ-caseins) is analyzed in detail. A comparative analysis of the content of amino acid residues in the polypeptide chains of caseins of the above types was carried out. Glycosylation sites, hydrophobic and hydrophilic regions of the molecules were identified. The main caseins of female breast milk (β-casein, κ-casein) and cow’s milk were carried out. The paper deals with topical issues of allergenic activity of cow’s milk caseins and their cross-reactivity with milk proteins of other mammalian species. Further study of the physicochemical and immunobiological properties of caseins will contribute to the development of various strategies to reduce allergic reactions caused by milk consumption. Some approaches will be aimed at changing the structure of the allergen by the method of technological processing of milk, while others will be aimed at reducing the sensitivity to milk allergens using immunotherapy.