AF005: Cystatin

List allergens from this family:

Routes of exposure:
Include only IUIS approved allergens.

Biochemical properties

The cystatin superfamily of reversibly binding cysteine protease inhibitors has been divided into three animal families, stefins, cystatins and kinenogens, and one plant cystatin family, phytocystatins [1]. Most phytocystatins are 12-14 kDa in size, contain no disulfide bonds, and show significant amino acid sequence similarity to the cystatin families of animal origin [2].

Allergens from this family

Allergens belonging to the phytocystatins are found in kiwifruit (Actinidia deliciosa), gold kiwifruit (Actinidia chinensis) [3], and short ragweed (Ambrosia artemisiifolia) [4]. Among animal cystatins, Fel d 3 from cat and Ani s 4 from Anisakis simplex were identified as allergens [5, 6].



  1. Abrahamson M:
    Methods Enzymol 1994, 244, 685-700. [PubMed]
  2. Nagata K, Kudo N, Abe K, Arai S, Tanokura M:
    Three-dimensional solution structure of oryzacystatin-I, a cysteine proteinase inhibitor of the rice, Oryza sativa L. japonica.
    Biochemistry 2000, 39, 14753-60. [PubMed]
  3. Bublin M, Mari A, Ebner C, Knulst A, Scheiner O, Hoffmann-Sommergruber K, Breiteneder H, Radauer C:
    IgE sensitization profiles toward green and gold kiwifruits differ among patients allergic to kiwifruit from 3 European countries.
    J Allergy Clin Immunol 2004, 114, 1169-75. [PubMed] [Full Text]
  4. Rogers BL, Pollock J, Klapper DG, Griffith IJ:
    Sequence of the proteinase-inhibitor cystatin homologue from the pollen of Ambrosia artemisiifolia (short ragweed).
    Gene 1993, 133, 219-21. [PubMed]
  5. Ichikawa K, Vailes LD, Pomes A, Chapman MD:
    Identification of a novel cat allergen--cystatin.
    Int Arch Allergy Immunol 2001, 124, 55-6. [PubMed] [Full Text]
  6. Rodriguez-Mahillo AI, Gonzalez-Munoz M, Gomez-Aguado F, Rodriguez-Perez R, Corcuera MT, Caballero ML, Moneo I:
    Cloning and characterisation of the Anisakis simplex allergen Ani s 4 as a cysteine-protease inhibitor.
    Int J Parasitol 2007, 37, 907-17. [PubMed] [Full Text]


Links to Pfam

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

Pfam domain Pfam clan
PF00031 Cystatin domain CL0121 Cystatin-like superfamily
PF16845 Aspartic acid proteinase inhibitor CL0121 Cystatin-like superfamily

Links to Wikipedia


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