Pectate lyase Amb a 1 (Amb a 1) (Amb a 1)

Amb a 1 is the immunodominant major allergen of short ragweed (Ambrosia artemisiifolia) pollen, belonging to the pectate lyase family (UniProt: P13347) [1]. In the plant, it functions as an enzyme that degrades pectin in the cell wall, a process essential for pollen tube germination and growth [4]. In humans, Amb a 1 is responsible for triggering seasonal allergic rhinitis (hay fever) and allergic asthma in the majority of ragweed-sensitized individuals [2]. The protein is a 38 kDa acidic glycoprotein that typically dissociates into two fragments, alpha and beta, which remain associated through non-covalent interactions to maintain its allergenic epitopes [1, 4]. As a therapeutic target, Amb a 1 is the primary constituent of allergen-specific immunotherapy (AIT) products, such as Ragwitek, which are designed to induce clinical tolerance [3]. These therapies work by modulating the immune system, specifically by inducing regulatory T cells and increasing the levels of allergen-specific IgG4 antibodies to block IgE-mediated mast cell degranulation [3, 5].

Other names

Antigen EShort ragweed allergen Amb a 1Amb a IPectate lyase

Allergen-specific immunotherapy (AIT) induces immune tolerance by promoting the development of regulatory T cells (Tregs), shifting the cytokine profile from Th2 to Th1, and stimulating the production of allergen-specific IgG4 antibodies that compete with IgE for allergen binding [3, 5].