Flashcards in 59-Antibody Structure and Function Deck (48)
Loading flashcards...
1
antigen receptors
on surface of lymphocytes
B cell receptors
T cell receptors
many different receptors to recognize unlimited number of foreign Ags
clonically expressed-1 unique Ag receptor per lymphocyte clone
2
Surface BCR and soluble Ab molecules
identical except small transmembrane sequence on C terminal end
3
function of BCR
recognition of antigen
initiates signal transduction using CD79a/b to start intracellular signaling
4
CD79
needed for BCR to start intracellular signalling
5
structure of Ab
2 heavy chains
2 light chains
hinge region for torsion
disulfide bonds to hold molecules together
N linked carb chains linked to heavy chain for 3D structure and half life
6
variable region
heavy-VDJ
light-VJ
form antigen binding pocket, 2 identical pockets that bind identical antigens
7
constant region
no recombination, ensure structural integrity
H chain is for key effector functions
8
Fab region
Ag binding, 2 Fab regions=Fab2, bind 2 identical antigens
9
Fc region
below hinge region, heavy chain constant region
effector functions
10
Fab
cleave above hinge
11
Fc
cleave above hinge
12
Fab2
cleave below hinge
13
hypervariability regions
3 regions in both heavy and light, "complementarity determining regions"
1 and 2 and encoded in DNA
3 is recombination of VDJ or VJ
14
CDR
complementarity determining regions, variability in heavy and light chains
proximal in tertiary structure and form Ag binding pocket
15
epitope
small segment of Ag bound by Ag binding pocket, non covalent interactions
16
what can TCRs recognize vs BCR/Ag
TCR-peptides, require MHC
BCR/Ag-lipid, carb, protein, nucleic acid, interact with epitopes on surface of pathogens, do not require MHC
17
end product of B cell activation
cell that secretes Abs (soluble version of BCR) that recognize pathogen epitope and bind then recruite innate immunity to mediate destruction
18
Ab isotypes
defined by heavy chain constant region
5 isotopes encoded by loci
IgM, G, A, E, D
19
subclasses of Ab
IgG-4
IgA-2
20
IgM structure
4 constant regions, no hinge
large and inflexible=only in blood
secreted as pentamer-10 binding sites
21
antibody that is a pentamer
IgM
22
IgM functions
neutralization
agglutination
complement activation
23
neutralization Abs
IgM, IgG, IgA
24
agglutination Abs
IgM, IgG, IgA
25
complement activation Abs
IgM, IgG
26
IgG structure
3 constant regions with hinge
secreted as monomer-2 binding sites
most abundant
found in blood and tissues
27
antibody that is a monomer
IgG, IgA in blood, IgE
28
IgG functions
neutralization
agglutiniation
complement activation
opsonization/phagocytosis
Ab dependent cellular cytotoxicity
transplacental transfer
29
opsonization/phagocytosis Abs
IgG, IgA
30
