Fel d 1

Major allergen I polypeptide chain 2
Crystallographic structure of the Fel d 1 dimer, the primary allergen present in cat saliva.[1]
Identifiers
Symbol CH2
Alt. symbols Fel d I, AG4, Allergen Cat-1
Entrez 677879
PDB 1PUO
UniProt P30440
Other data
Allergen Fel d I-B chain
structural characterization of the tetrameric form of the major cat allergen fel d 1
Identifiers
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.

Cats produce, on average, 2-7 µg of Fel d 1 per day. 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. 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.

Structure

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

References

  1. ^ a b c PDB 1PUO; Kaiser L, Grönlund H, Sandalova T, Ljunggren HG, van Hage-Hamsten M, Achour A, Schneider G (September 2003). "The crystal structure of the major cat allergen Fel d 1, a member of the secretoglobin family". J. Biol. Chem. 278 (39): 37730–5. doi:10.1074/jbc.M304740200. PMID 12851385. 
  2. ^ Morgenstern JP, Griffith IJ, Brauer AW, Rogers BL, Bond JF, Chapman MD, Kuo MC (November 1991). "Amino acid sequence of Fel dI, the major allergen of the domestic cat: protein sequence analysis and cDNA cloning". Proc. Natl. Acad. Sci. U.S.A. 88 (21): 9690–4. doi:10.1073/pnas.88.21.9690. PMC 52784. PMID 1946388. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=52784. 
  3. ^ Griffith IJ, Craig S, Pollock J, Yu XB, Morgenstern JP, Rogers BL (April 1992). "Expression and genomic structure of the genes encoding FdI, the major allergen from the domestic cat". Gene 113 (2): 263–8. doi:10.1016/0378-1119(92)90405-E. PMID 1572548. 

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