Fel d 1

Allergen Fel d 1, chain 2 (P30440)
Allergen Fel d 1, chain 2 (P30440)
	Crystallographic structure of the Fel d 1 dimer, the primary allergen present in cat saliva
Identifiers
Symbol	Feld-I_B
Pfam	PF09252
Pfam clan	CL0370
InterPro	IPR015332
SCOP2	1puo / SCOPe / SUPFAM
PDB
Available protein structures:
PDB	IPR015332 PF09252 (ECOD; PDBsum)
AlphaFold	IPR015332; PF09252;

Available protein structures:
PDB	IPR006178
AlphaFold	IPR006178;

Allergen Fel d 1, chain 1 (P30438)
Allergen Fel d 1, chain 1 (P30438)
Identifiers
Symbol	Allergen_Fel_d_I_chain1
InterPro	IPR006178
PDB
Available protein structures:
PDB	IPR006178
AlphaFold	IPR006178;

Fel d 1 is a secretoglobin protein complex that, in cats, is encoded by the CH1 (chain 1/Fel d 1-A) and CH2 (chain 2/Fel d 1-B) genes.

Among cats, Fel d 1 is produced largely in their saliva and by the sebaceous glands located in their skin. It is the primary allergen present on cats and kittens - it causes allergy in 90% of people with cat allergy. The function of the protein for cats is unknown, but it causes an IgG or IgE reaction in sensitive humans (either as an allergic or asthmatic response).