AF046: Kunitz soybean trypsin inhibitor family

List allergens from this family:

Routes of exposure:
Include only IUIS approved allergens.

Biochemical properties

The Kunitz-type soybean trypsin inhibitor (STI) family consists mainly of proteinase inhibitors from legume seeds. The STIs belong to the β-trefoil superfamily that also contains the interleukin-1 proteins, heparin binding growth factors and histactophilin, all of which have very similar structures, but share no sequence similarity with the STI family [1].

Allergens from this family

The Kunitz trypsin inhibitor from soybean was identified as a minor allergen [2]. In potato, three protease inhibitors bound IgE from about half of the sera of atopic children [3].



  1. Murzin AG, Lesk AM, Chothia C:
    beta-Trefoil fold. Patterns of structure and sequence in the Kunitz inhibitors interleukins-1 beta and 1 alpha and fibroblast growth factors.
    J Mol Biol 1992, 223, 531-43. [PubMed]
  2. Burks AW, Cockrell G, Connaughton C, Guin J, Allen W, Helm RM:
    Identification of peanut agglutinin and soybean trypsin inhibitor as minor legume allergens.
    Int Arch Allergy Immunol 1994, 105, 143-9. [PubMed]
  3. Seppala U, Majamaa H, Turjanmaa K, Helin J, Reunala T, Kalkkinen N, Palosuo T:
    Identification of four novel potato (Solanum tuberosum) allergens belonging to the family of soybean trypsin inhibitors.
    Allergy 2001, 56, 619-26. [PubMed]


Links to Pfam

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

Pfam domain Pfam clan
PF00197 Trypsin and protease inhibitor CL0066 Beta-trefoil superfamily

Links to Wikipedia


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