Diebel Antibodies Part 1 Flashcards
Two varieties of light chains:
kappa
lamda
The 5 kinds of H chains:
(gamma, alpha, mu, epsilon, delta)
When a cell switches from making IgM to IgA, which chain swithces?
Heavy, light stays the same
Portion of antibody that binds an antigen?
Variable domain
*both H and L chains have a V domain
Slight differences in the amino acid sequences of antibody H chain C regions?
Isotypes
Minor allelic differences in the sequence of immunoglobulins between individuals:
Allotypes
*similar to eye color, etc.
Each antibody will have its unique combining region, made up of the CDR amino acids of its L and H chains; we can call this unique structure an:
Idiotype
The main antibody in blood and tissue fluids. It neutralizes toxins and blood-borne viruses, binds bacteria and facilitates their destruction by activating complement and by binding them to phagocytic cells.
IgG
Real role is as the dimer form in secretions, where secretory component protects it from proteolysis.
IgA
First antibody to appear in the serum after
immunization, and it is very efficient at activating complement. It does not get into tissue fluids very efficiently, nor is it bound efficiently by phagocytic cells.
IgM
Seems to function mainly as a receptor on naïve B
cells.
IgD
The antibody which causes Type I immunopathology, also called immediate hypersensitivity or allergy. Its true importance is in resistance to worms and other parasites.
IgE
Relative antibody concentrations in human serum: IgG IgA IgM IgD IgE
IgG: 1000 mg/deciliter (dL =100 mL) IgA: 200 mg/dL IgM: 100 mg/dL IgD: 5 mg/dL IgE: 0.02 mg/dL
What part of an antibody binds C1q? Why does this make IgM the best at activating complement?
Fc
*C1q must bind two adjacent Fc’s that are relatively close together
because IgM has 5 Fc’s at all times
