Antigen 5 protein (Ag5)

Antigen 5 proteins are highly allergenic components of Hymenoptera (wasp and ant) venoms, structurally belonging to the CAP superfamily and playing a central role in allergic sensitization to insect stings. They are compact, globular proteins (~22 kDa) characterized by a conserved α-β-α sandwich fold, containing a CAP domain with putative active sites likely involved in immune modulation. Antigen 5 is widely used in molecular diagnostics to improve specificity in venom allergy detection and is a critical component in venom immunotherapy. However, "Antigen 5" is a collective term for related, but not identical, proteins present in venoms from different insects, and is not a unique human receptor or enzyme. Accurate context and species specification are essential for any structured data use.

Other names

Ves v 5 (yellow jacket antigen 5)Poly p 5 (Polybia paulista wasp antigen 5)Sol i 3 (fire ant antigen 5)Ag5Hymenoptera venom allergen 5

Elicits IgE-mediated allergic immune responses; Used as a molecular component in allergy diagnostics and immunotherapeutic approaches