logo
Products
Services
Resources
Selection Guides
About
What are the differences between the subclasses of immunoglobulin A (IgA)?
Posted July 31, 2024
Antibodies and Proteomics Bioconjugation Chemical ReagentsAntibody and Protein LabelingPhysiological Probes
Answer
Basis of differentiation
Immunoglobulin A1 (IgA1)
Immunoglobulin A2 (IgA1)
Percentage of total IgA in serum
85%
15%
Hinge region 
Elongated, increasing sensitivity to bacterial proteases
Shorter, providing more resistance to proteases
Protease resistance
Broad resistance but some proteases can cleave the hinge region
Good resistance to proteolysis and many bacterial proteases
Immune response
Strong response to protein antigens; Moderate response to lipopolysaccharides and polysaccharides
Plays a crucial role in mucosal immunity, fighting polysaccharide and lipopolysaccharide antigens
Presence in body
More than 90% in serum; less prevalent in mucosal secretions
Predominates in mucosal secretions such as the gastrointestinal tract and airways
Allotypic variants
Not specified
Two variants defined serologically and molecularly - IgA2m(1) and IgA2m(2)
Disulfide bridges
Typical disulfide bridges linking light and heavy chains
  • IgA2m(1) generally lacks disulfide bridges
  • IgA2m(2) has typical disulfide bridges  
Additional resources
IgA: Structure, Function, and Developability Antibodies and Proteomics Purified Mouse Anti-human IgA Secretory Component Antibody *SC-05, monoclonal*

Why is it important to eliminate non-specific binding?Why might polyclonal antibodies give better results than monoclonal antibodies?What are the functions of immunoglobulin D (IgD)?What are the commonly used self-labeling tags?How to eliminate non-specific binding?