Which immunoglobulin class predominantly exists as a pentamer in the serum?

Study for the NBME Immunology Test. Study with flashcards and multiple choice questions, each question includes hints and explanations. Prepare to excel!

Multiple Choice

Which immunoglobulin class predominantly exists as a pentamer in the serum?

Explanation:
IgM is the immunoglobulin class that predominantly exists as a pentamer in the serum. This pentameric form arises when five IgM units come together with a joining chain, creating ten antigen-binding sites. The high valency gives IgM very strong overall binding (high avidity) to multivalent antigens, which makes it especially effective at agglutination and at activating the classical complement pathway. This is why IgM is produced first in a primary immune response. Other isotypes are monomeric (IgG and IgE) or, for IgA, typically dimeric in secretions (though serum IgA is usually monomeric). Thus, the pentameric arrangement in serum points to IgM as the predominant form.

IgM is the immunoglobulin class that predominantly exists as a pentamer in the serum. This pentameric form arises when five IgM units come together with a joining chain, creating ten antigen-binding sites. The high valency gives IgM very strong overall binding (high avidity) to multivalent antigens, which makes it especially effective at agglutination and at activating the classical complement pathway. This is why IgM is produced first in a primary immune response. Other isotypes are monomeric (IgG and IgE) or, for IgA, typically dimeric in secretions (though serum IgA is usually monomeric). Thus, the pentameric arrangement in serum points to IgM as the predominant form.

More Multiple Choice Questions
Subscribe

Get the latest from Passetra

You can unsubscribe at any time. Read our privacy policy