Thaumatin-like protein (TLP)

Thaumatin-like proteins (TLPs) are a diverse and evolutionarily conserved family of proteins belonging to the pathogenesis-related protein 5 (PR-5) group, found in plants, fungi, and some animals. They are characterized by a stable three-dimensional "TLP-fold" reinforced by multiple disulfide bonds, which provides resistance to heat, pH changes, and proteolytic degradation. Biologically, TLPs function as critical defense molecules, exhibiting antifungal activity by permeabilizing fungal membranes and inhibiting enzymes like β-1,3-glucanases and xylanases. In clinical medicine, TLPs are recognized as major allergens (e.g., Mal d 2 in apple, Pru av 2 in cherry) that cause food and pollen allergies, often manifesting as oral allergy syndrome or life-threatening anaphylaxis. While they are not conventional targets for small-molecule drugs, they are the primary focus of allergy diagnostics and specific immunotherapy (SIT), and emerging research suggests their potential as neuroprotective agents or as targets for novel antifungal therapies.

Other names

PR-5 proteinPathogenesis-related protein 5Osmotin-like protein (OLP)ZeamatinPermatinPru av 2Mal d 2Mus a 4Ole e 13Act d 2

Induction of immunological tolerance through repeated exposure to the allergen in immunotherapy; IgE-mediated mast cell degranulation in allergic responses; fungal membrane permeabilization in defense.