AF085: Kappa-casein

List allergens from this family:

Routes of exposure:
Include only IUIS approved allergens.

Biochemical properties

Caseins are a family of phosphoproteins (αS1, αS2, β, κ) that account for nearly 80% of bovine milk proteins and that form soluble aggregates known as casein micelles in which κ-casein molecules stabilize the structure. The specific cleavage of κ-casein by chymosin is the first step in the milk clotting process. Gastro-intestinal proteases cleave κ-casein, converting it into an insoluble peptide (para κ-casein) and a soluble hydrophilic glycopeptide called caseinomacropeptide [1]. Caseinomacropeptide is responsible for increased efficiency of digestion, prevention of neonate hypersensitivity to ingested proteins, and inhibition of gastric pathogens.

Allergens from this family

Allergenic members of this family include milk allergens from cow, sheep and goat [2, 3].



  1. Visser S, Van Rooijen PJ, Slangen CJ:
    Peptide substrates for chymosin (rennin). Isolation and substrate behaviour of two tryptic fragments of bovine kappa casein.
    Eur J Biochem 1980, 108, 415-21. [PubMed]
  2. Wal JM:
    Bovine milk allergenicity.
    Ann Allergy Asthma Immunol 2004, 93, S2-11. [PubMed]
  3. Roncada P, Gaviraghi A, Liberatori S, Canas B, Bini L, Greppi GF:
    Identification of caseins in goat milk.
    Proteomics 2002, 2, 723-6. [PubMed] [Full Text]


Links to Pfam

Family-defining Pfam domains (at least one of these domains is present in each family member):

Pfam domain Pfam clan
PF00997 Kappa casein -

Links to Wikipedia


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