Enhanced Anti-Allergic Activity of Milk Casein Phosphopeptide by Additional Phosphorylation in Ovalbumin-Sensitized Mice

Abstract

The proteolytic digest of milk casein, known as casein phosphopeptide (CPP-III), exhibits diverse biological activities, including calcium absorption and antioxidant activities. We hypothesized that the additional phosphorylation of this peptide can enhance its immunomodulatory activity such as suppression of allergy-associated cytokine and antigen-specific immune response. This study was conducted to assess whether oral intake of additionally phosphorylated CPP-III (P-CPP) attenuates ovalbumin (OVA)-induced IgE-mediated allergic reactions because of the additional phosphate groups. Female BALB/c mice were intraperitoneally sensitized with OVA twice at intervals of 14 days and then orally fed native CPP-III (N-CPP), P-CPP, and dephosphorylated CPP-III (D-CPP) for 6 weeks. Next, the mice were orally challenged with 50 mg of OVA. Oral administration of P-CPP suppressed total and specific IgE levels in the serum. Mice fed P-CPP exhibited low levels of OVA-specific IgG1 and increased OVA-specific IgG2a. P-CPP also suppressed IL-4 production, while D-CPP showed similar a level compared to that of the control. Further, P-CPP increased the population of the T follicular helper (Tfh) cell in the spleen. These results suggest that additional phosphorylation of CPP can enhance the attenuation of allergen-specific IgE-modulated allergic reactions in a murine food allergy model.

Overview of protein posttranslational modifications in Arthropoda venoms

“…This modified mature form was recognized by a pool of human specific-IgE. Although the exact role of Tyr 111 phosphorylation in this protein is still unknown, allergen with multi phosphorylation was associated with decreased affinity to specific-IgE, attenuating allergic reactions [51]. The other Ag5 from Vespa velutina was identified in UniProtKB/Swiss-Prot as putative by sequence similarity with the previously mentioned one, but with phosphorylation at Tyr 107 .…”

Discovery of calcium-binding peptides derived from defatted lemon basil seeds with enhanced calcium uptake in human intestinal epithelial cells, Caco-2

“…Numerous studies have argued that the binding of calcium and peptides depends upon the particular groups that are found in the peptide sequence. The groups that most frequently appear in the literature in the context of calcium binding are phosphate and carboxyl groups 49 , 50 . In the human diet, milk casein from cows and egg yolk casein contain phosphorylated groups, including CPPs and phosvitin phosphopeptides (PPPs), which are able to aggregate calcium via highly polar acidic motifs.…”

Quantitative Phosphoproteome of Infant Formula: New Insights into the Difference of Phosphorylation in Milk Proteins between Bovine and Goat Species

“…For example, casein can be phosphorylated to form casein micelles, colloidal particles, which stabilize calcium and phosphate ions in the protein complex and effectively deliver nutrients to the newborn without causing pathological calcification or amyloidosis . Furthermore, the phosphorylation level of milk proteins has been associated with lactation, coagulation properties, digestibility, and allergenicity. − With the development of phosphoproteomics, the phosphorylated peptides, and phosphorylated sites have been investigated in both raw bovine and goat milk. − A number of 20 phosphorylated peptides, including 7 phosphorylated forms of α-S1-casein (CSN1S1), 8 of α-S2-casein (CSN1S2), and 5 of β-casein (β-CN) were reported in bovine milk . In another work, 8 phosphorylated peptides, including 2 phosphorylated forms of CSN1S1, 4 of CSN1S2, and 2 of β-CN with 18 phosphorylation sites, were identified in goat milk .…”