Immunology Lecture 14: Structure and Function of Antibodies
how many domains are constant in the light chain of IgG?
1
how many domains are variable in the heavy chain of IgG?
1
how many domains are variable in the light chain of IgG?
1
IgM can be found in both the blood and tissues. True or false?
False (it is very rare for it to be found in tissue fluids due to its size)
IgA is held together by an F chain. True or false?
False, it is held together by a J chain.
this antigen is a dimer
IgA
this class of antibody is the predominant immunoglobulin in secretions such as saliva, milk, and intestinal fluid.
IgA
this immunoglobulin is produced on body surfaces and is responsible for the defense of the intestinal and respiratory tract
IgA
this antibody is found in a mother's milk and helps provide intestinal immunity to the neonate.
IgA (mucosal!!!)
this antibody is found on B cell surfaces and has a regulatory function. It is important in B cell development.
IgD
this antibody is found on the surface of immature lymphocytes
IgD
this class of antibody is found in very low concentrations in serum and mediates allergic reactions.
IgE
this immunoglobulin is found in very small quantities in serum and is responsible for immunity to parasitic worms and allergies
IgE
This antibody has a half life of 3 weeks
IgG
functions of this antibody include: - complement activation - neutralization of viruses and toxins - opsonization - systemic immunity of newborns - antibody dependent cell-mediated cytotoxicity (NK cells)
IgG
this antibody is found in high concentrations in colostrum of large domestic species and makes up 80% of total serum antibody.
IgG
this antibody is the predominant immunoglobulin in serum and is mainly responsible for systemic defense
IgG
this class of antibody can escape from blood vessels more easily than others, making it especially important in inflammation.
IgG
this class of antibody has the highest concentrations in serum and is produced by plasma cells in the spleen, lymph nodes, and bone marrow.
IgG
this class of antibody is the second highest in concentration in serum and is produced by plasma cells in secondary lymphoid organs.
IgM
this is a very large antibody mainly produced during the primary immune response
IgM
this is the major antibody produced during a primary immune response
IgM
(IgM/IgG) predominates in a primary immune response while (IgM/IgG) predominates in a later response.
IgM, IgG
IgM is held together by disulfide bonds and ___ chain.
J
where is most of IgE found?
bound to mast cells
hypervariable regions that come together to form the antigen binding site when the protein folds
complimentary determining region
what can result from the binding of IgE to a mast cell?
degranulation
IgD uses what type of heavy chains?
delta
holds the chains together and are also important in the structure of the domain loops
disulfide bonds
IgE can activate this granulocyte (think of mutual function)
eosinophils
the part of the antigen that the antibody binds to (an antigen can have more than one of these)
epitopes
IgE uses what type of heavy chains?
epsilon
what is the function of IgA?
found on mucosal surfaces where it can neutralize toxins and block entry of pathogens
this part of the antibody dictates biological activity (including opsonization, binding of mast cells, and complement fixation)
fragment crystallizable (Fc)
IgG uses what type of heavy chains?
gamma
what are the two forms of light chain for an antibody?
lambda or kappa
the Fc portion of IgE has a high affinity for the Fc receptor on this type of cell
mast cell
IgM is (monomeric/pentameric) when it is cell-bound and is (monomeric/pentameric) when it is secreted.
monomeric, pentameric
IgM uses what type of heavy chains?
mu
where will you find IgA in the body?
mucosal surfaces (intestine, respiratory tract, urinary system, skin, mammary gland)
antigen-antibody binding is covalent or non-covalent?
non-covalent
this is a peptide that binds IgA dimers and is added to IgA as it is transported to the mucosal surface
secretory component
List the 5 classes of antibodies
1. IgG 2. IgM 3. IgD 4. IgA 5. IgE
2 major functions of IgM
1. complement activation 2. agglutination
what are the 2 functions of IgE?
1. important in defense against parasites 2. mediator of immediate hypersensitivity
how many epitopes can IgM bind?
10
what is the molecular weight of IgG?
180,000 Da
what is the molecular weight of IgE?
190,000 Da
How many domains form the light chain of IgG?
2
how many domains form the constant domain in the heavy chain of IgG?
3
how many daltons is the light chain of IgG?
30,000
what is the molecular weight of IgA?
360,000 Da
IgG has ______ heavy chain domains
4
IgG has a light chain and a heavy chain. How many domains form the heavy chain?
4
how many domains does the heavy chain have in IgA?
4
how many domains does the heavy chain have in IgM?
5
how many domains make up the heavy chain in IgE?
5
how many daltons is the heavy chain of IgG?
60,000
what is the molecular weight of IgM?
900,000 Da
all antibodies originate as _______ shed into body fluids
BCRs
From ______ and beyond are the Fc region of the antibody CL CH2 CH3
CH2
what two parts of the constant chain make up the Fc region on IgG?
CH2 and CH3
Select 1 (or more if applicable) which of the following form the antigen binding site? VH VL CH1 CL CH2 CH3
VH and VL (variable heavy domain and variable light domain)
Select 1 (or more if applicable) Which of the following form the fragment antigen binding? VH VL CH1 CL CH2 CH3
VH, VL, CH1, CL (this is the antigen binding end of the molecule)
IgA uses what type of heavy chains?
alpha
this determines the class (isotype) of antibody
the type of heavy chain
heavy chains on an antibody are identical. true or false?
true
light chains on an antibody are identical. true or false?
true
is antigen-antibody binding reversible?
yes
