Antibody Antigen interactions
Explain what an antigen is
An antigen is any molecule that can be bound by an antibody.
explain what an epitope is
An epitope (also called an “antigenic determinant”) is the region of the antigen that is bound (contacted) by an antibody.
Describe the types of molecules that most biologically-relevant antigens comprised of?
antigens and epitopes
A single antigen may have many different or identical epitopes
Describe the physical aspects of antibody/antigen binding.
Describe the chemical aspects of antibody/antigen binding
(the
types of non-covalent bonds that account for antibody/antigen binding)
Hydrogen bonding
ionic bonding
hydrophobic interactions
van der waals interactions
Antibody X (IgG) binds to a bacterial protein called protein Q. Which of the following changes would likely result in the loss of antibody binding to protein Q? Chose all correct answers.
a.) Changing the amino acid sequences of the CDRs of the two light chains.
b.) Changing the conformation of the CDRs of the two heavy chains.
c.) Changing the isotype of antibody X from IgG to IgA.
d.) Replacing the two constant light chain domains (CL) with the constant light chain domain from a different antibody.
e.) Changing the amino acids in protein Q that form the epitope bound by antibody X.
a.) Changing the amino acid sequences of the CDRs of the two light chains.
b.) Changing the conformation of the CDRs of the two heavy chains.
e.) Changing the amino acids in protein Q that form the epitope bound by antibody X.
the difference between a linear epitope and a conformationally-dependent (discontinuous) epitope.
Linear: linear sequence of amino acids
Discontinuous: The amino acids are being bond to the CDRs
Explain the difference between antibody affinity and antibody avidity
Affinity: is the strength of binding between a single Fab region of an antibody and a single epitope
Avidity: The collective strength of binding between multiple Fab regions of a single antibody (or antibody complex like pentameric Igm) with multiple epitopes
Explain how the Coggin’s test is performed
Explain how the Coggin’s test is used to determine a horse’s prior exposure to equine infectious anemia virus (EIAV)
what is a conjugated antibody?
What types of molecules are commonly conjugated to antibodies?
Explain how an ELISA is performed
understand the roles of antibody and antigen in the assay
Explain how a Western blot is performed and the roles of antibody and antigen in the assay.
Explain what a primary antibody is and what a secondary antibody as
it pertains to the antibodies used in some types of
immunoassays
such as ELISA and immunohistochemistry.