the sweet-tasting protein, thaumatin, and thaumatin-like proteins involved in host defense. This family is represented by the sweet-tasting protein thaumatin from the African berry Thaumatococcus daniellii and thaumatin-like proteins (TLPs) involved in host defense and a wide range of developmental processes in fungi, plants, and animals. Plant TLPs are classified as pathogenesis-related (PR) protein family 5 (PR5), their expression is induced by environmental stresses such as pathogen/pest attack, drought and cold. TLPs included in this family are such proteins as zeamatin, found in high concentrations in cereal seeds; osmotin, a salt-induced protein in osmotically stressed plants; and PpAZ44, a propylene-induced TLP in abscission of young fruit. Several members of the plant TLP family have been reported as food allergens from fruits (i.e., cherry, Pru av 2; bell pepper, Cap a1; tomatoes, Lyc e NP24) and pollen allergens from conifers (i.e., mountain cedar, Jun a 3; Arizona cypress, Cup a3; Japanese cedar, Cry j3). Thaumatin and TLPs are three-domain, crescent-fold structures with either an electronegative, electropositive, or neutral cleft occurring between domains I and II. It has been proposed that the antifungal activity of plant PR5 proteins relies on the strong electronegative character of this cleft. Some TLPs hydrolyze the beta-1,3-glucans of the type commonly found in fungal walls. Most TLPs contain 16 conserved Cys residues. A deletion within the third domain (domain II) of the Triticum aestivum thaumatin-like xylanase inhibitor is observed, thus, only 10 conserved Cys residues are present within this smaller TLP and similar homologs.
thaumatin and allergenic/antifungal thaumatin-like proteins: plant homologs. This subfamily is represented by the sweet-tasting protein thaumatin from the African berry Thaumatococcus daniellii, allergenic/antifungal Thaumatin-like proteins (TLPs), and related plant proteins. TLPs are involved in host defense and a wide range of developmental processes in fungi, plants, and animals. Plant TLPs are classified as pathogenesis-related (PR) protein family 5 (PR5), their expression is induced by environmental stresses such as pathogen/pest attack, drought and cold. TLPs in this subfamily include such proteins as zeamatin, found in high concentrations in cereal seeds, and osmotin, a salt-induced protein in osmotically stressed plants. Several members of the plant TLP family have been reported as food allergens from fruits (i.e., cherry, Pru av 2; bell pepper, Cap a1; tomatoes, Lyc e NP24) and pollen allergens from conifers (i.e., mountain cedar, Jun a 3; Arizona cypress, Cup a3; Japanese cedar, Cry j3). Thaumatin and TLPs are three-domain, crescent-fold structures with either an electronegative, electropositive, or neutral cleft occurring between domains I and II. It has been proposed that the antifungal activity of plant PR5 proteins relies on the strong electronegative character of this cleft. IgE-binding epitopes of mountain Cedar (Juniperus ashei) allergen Jun a 3, which interact with pooled IgE from patients suffering allergenic response to this allergen, were mainly located on the helical domain II; the best-conserved IgE-binding epitope predicted for TLPs corresponds to this region. Some TLPs hydrolyze the beta-1,3-glucans of the type commonly found in fungal walls. Most TLPs contain 16 conserved Cys residues. A deletion within the third domain (domain II) of the Triticum aestivum thaumatin-like xylanase inhibitor is observed, thus, only 10 conserved Cys residues are present within this smaller TLP and similar homologs.
allergenic/antifungal thaumatin-like proteins: plant and animal homologs. This subfamily is represented by the thaumatin-like proteins (TLPs), Cherry Allergen Pru Av 2 TLP, Peach PpAZ44 TLP (a propylene-induced TLP in abscission), the Caenorhabditis elegans thaumatin family member (thn-6), and other plant and animal homologs. TLPs are involved in host defense and a wide range of developmental processes in fungi, plants, and animals. Due to their inducible expression by environmental stresses such as pathogen/pest attack, drought and cold, plant TLPs are classified as the pathogenesis-related (PR) protein family 5 (PR5). Several members of the plant TLP family have been reported as food allergens from fruits (i.e., cherry, Pru av 2; bell pepper, Cap a1; tomatoes, Lyc e NP24) and pollen allergens from conifers (i.e., mountain cedar, Jun a 3; Arizona cypress, Cup a3; Japanese cedar, Cry j3). TLPs are three-domain, crescent-fold structures with either an electronegative, electropositive, or neutral cleft occurring between domains I and II. It has been proposed that the antifungal activity of plant PR5 proteins relies on the strong electronegative character of this cleft. Some TLPs hydrolyze the beta-1,3-glucans of the type commonly found in fungal walls. TLPs within this subfamily contain 16 conserved Cys residues.
Thaumatin family. The thaumatin family gathers proteins related to plant pathogenesis. The thaumatin family includes very basic members with extracellular and vacuolar localization. Thaumatin itsel is a potent sweet-tasting protein. Several members of this family display significant in vitro activity of inhibiting hyphal growth or spore germination of various fungi probably by a membrane permeabilizing mechanism.