What are the properties of immunoglobulin A (IgA)?

Immunoglobulin A (IgA) is the second most abundant immunoglobulin (Ig) found in humans, accounting for 10-15% of the total Ig quantity in serum. It has a molecular weight of 400,000 Da and exists in two forms – monomeric and polymeric

Secretory IgA molecules are comprised of two 4-chain basic units and the J-chain is connected by a short peptide