Characterisation of horse dander allergen glycoproteins using amino acid and glycan structure analyses. a mass spectrometric method for glycan chain analysis of glycoproteins separated by two-dimensional electrophoresis.

The research article discusses a method of analyzing and identifying the structures of glycan chains in the most common isoforms of Equ c 1, a major allergen extracted from horse dander, using two-dimensional PAGE (Polyacrylamide Gel Electrophoresis).

Methodology

• To separate the allergens, a method of two-dimensional Polyacrylamide Gel Electrophoresis (PAGE) was utilized.
• These separated allergens were then moved to Polyvinylidene difluoride membranes.
• The glycan chains were then detached using an enzyme known as peptide N-glycosidase F.
• The process was followed by permethylation and the derivatized glycans were analyzed using mass spectrometry.

Discovery and Analysis

• This method led to the identification of 16 proteins from horse dander that reacted with allergic patient sera.
• The amino acid compositions of these identified allergens were recognized.
• This facilitated the identification of various isoforms of a major horse dander allergen, Equ c 1.
• The study confirmed the non-glycosylated allergens, Equ c 2.0101 and Equ c 2.0102, to be part of the lipocalin family and are likely to be isoforms of the same protein.

Results and Implications

• The results of the mass spectrometric method identified common biantennary and triantennary glycan chains.
• These carbohydrate chains are believed to have a role in the binding of IgE, an antibody that plays a crucial role in the body’s immune response.
• However, it is suggested that the overall structure of the glycoprotein including the glycan and protein components, rather than the glycan chains alone, could be accountable for triggering allergic responses.

The study provides crucial insights for further research on allergens, allergies, and immunology. It also highlights the importance of understanding the structure of major allergens in order to devise effective treatments and preventions.