Fel d 1

From Wikipedia
Major allergen I polypeptide chain 2
Fel d 1.png
Crystallographic structure of the Fel d 1 dimer, the primary allergen present in cat saliva.[1]
Symbol CH2
Alt. symbols Fel d I, AG4, Allergen Cat-1
Entrez 677879
UniProt P30440
Other data
Allergen Fel d I-B chain
PDB 2ejn EBI.jpg
structural characterization of the tetrameric form of the major cat allergen fel d 1
Symbol Feld-I_B
Pfam PF09252
Pfam clan CL0370
InterPro IPR015332
SCOP 1puo

Fel d 1 is a protein that in cats is encoded by the CH1 (chain 1/Fel d 1-A) and CH2 (chain 2/Fel d 1-B) genes.[2][3]

Fel d 1, produced largely by cat saliva and sebaceous glands, is the primary allergen present on cats. The protein is of an unknown function to the animal but causes an IgG or IgE reaction in sensitive humans (either as an allergic or asthmatic response). Removal of soft surfaces in the home (carpet, furniture), frequent washings of bed linens, HEPA filters and even washing cats have been proven to reduce the amounts of Fel d 1 present in the home. Fel d 1 is a particularly sticky protein and has been shown to cling to clothing and human hair and can be detected in environments where a cat has never been present.[citation needed]

Cats produce, on average, 2-7 µg of Fel d 1 per day.[citation needed] Studies have shown that intact males produce Fel d 1 in levels higher than castrated males, leading to the assumption that Fel d 1 is hormonally regulated by testosterone.[citation needed] Neutered males produce Fel d 1 in levels similar to females (both intact and spayed females produce Fel d 1 in similar levels). Even though females and neutered males produce Fel d 1 in lower levels, they still produce enough to cause allergic symptoms in sensitive individuals.


The complete primary structure of Fel d 1 has been determined.[1] The allergen is a tetrameric glycoprotein consisting of two disulphide-linked heterodimers of [chains 1 and 2. Fel d 1 chains 1 and 2 share structural similarity with uteroglobin, a secretoglobin superfamily member; chain 2 is a glycoprotein with N-linked oligosaccharides. Both chains share an all alpha-helical structure.[1]

See also[edit]


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This article incorporates text from the public domain Pfam and InterPro IPR015332

et:Fel d 1 pt:Fel d 1