AF044: CAP family

List allergens from this family:

Routes of exposure:
Include only IUIS approved allergens.

Biochemical properties

A number of eukaryotic extracellular proteins have been shown to be evolutionarily related. The family includes rodent sperm-coating glycoprotein, which is thought to be involved in sperm maturation, mammalian testis-specific protein (Tpx-1), mammalian cysteine rich secretory proteins (CRISP), glioma pathogenesis-related protein, reptile toxins, group 5 insect venom allergens, and plant pathogenesis-related proteins PR-1. The name "CAP familiy" derives from Cysteine rich secretory protein, Antigen 5 and Pathogenesis-related protein PR-1. Members of this family, albeit highly diverse, contain a conserved calcium-binding site [1].

Allergens from this family

Most allergens from this family are insect venom allergens including group 5 wasp allergens and group 3 ant allergens [2]. Allergens from the plant PR-1 family include the Bermuda grass pollen allergen Cyn d 24, the mugwot pollen allergen Art v 2 and the muskmelon allergen, Cuc m 3.



  1. Gibbs GM, Roelants K, O'Bryan MK:
    The CAP superfamily: cysteine-rich secretory proteins, antigen 5, and pathogenesis-related 1 proteins--roles in reproduction, cancer, and immune defense.
    Endocr Rev 2008, 29, 865-97. [PubMed] [Full Text]
  2. Hoffman DR:
    Hymenoptera venom allergens.
    Clin Rev Allergy Immunol 2006, 30, 109-28. [PubMed]


Links to Pfam

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

Pfam domain Pfam clan
PF00188 Cysteine-rich secretory protein family -

Links to Wikipedia


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