Gross Structure of Antibodies Flashcards
What is another name of antibodies?
Immunoglobulins or IGs
What is the B cell receptor?
A membrane bound form of an antibody with the same structural features and same antigen specificity
What are the 5 classes or isotypes of antibodies?
IgA, IgD, IgE, IgG, and IgM
Epitope
A small specific area on a pathogen which is recognized by an antibody
The specificity of an antibody is determined by which region?
The variable region
The constant region determine what of an antibody?
Function
The constant region of an antibody determines what?
Function
What four polypeptide chains makeup an antibody molecule?
2 H chains and 2 L chains
What is the V region?
The N-terminus of each chain, known as the variable region
What is the C region of an antibody?
The rest of the H or L chain that differs only in determining isotype
What type of polymer is Igm?
Pentamer or hexamer
What type of polymer is IgA?
Dimer or monomer
What bonds hold together the H and L chains?
Disulfide
Which chains do not interact?
The two L chains
How many disulfide bonds hold the H chains together?
2
How many bonds hold an H chain and L chain together?
1
What are the two types of L chains?
Kappa and Lambda
How many amino acids are found in a domain?
About 110
How many domains does an H chain have?
3
How many domains does and L chain have?
1
How many domains are found in IgG, IgA, and IgD?
3
How many domains are found in IgM and IgE?
4
Which isotypes do not have a hinge?
IgE and IgM
What is the single effector function of B cells?
To produce antibodies
Which isotypes have 4 Ch domains?
IgM and IgE
Which isotypes have 3 constant domains?
IgA, IgD, and IgG
Domains have about how many amino acids?
110
Which portion of the antibody determines its function?
The constant region
What is the ratio in weight of heavy chain to light chain?
2:1
What is fab?
The fraction antigen binding site
What is Fc?
Fraction crystallizable
Which isotypes have the hinge present?
IgG, IgA, and IgD
Which enzyme must antibodies be treated with to make Fab and Fc?
Papain
True or False. Fab can retain the ability to mind antigen.
True
Which region contains the hinge? Fab or Fc.
Fc
What is the function of the Fc region?
Opsonization and deliver the antibody to specific anatomical sights
Which enzyme is used to make F(ab’)2?
Pepsin
What pieces are found in F(ab’)2?
Both Fab regions and the hinge
Where is the hinge found?
Between Ch1 and Ch2
Which residues primarily makeup the hinge region?
Pro, Ser, and Thr
How many epitopes does the hinge allow Fab to bind?
2
Which isotypes are associated with the J chain?
IgA and IgM
Which form of IgM does not have a J chain?
Hexameric IgM
How many J chains are found per antibody polymer?
1
What is transcytosis?
Transport of antibodies from the basal side of the epithelium to the mucosal surface
Papain digestion results in how many pieces?
3
Pepsin digestion results in how many pieces?
1 the F(ab’)2
