2 IG structure Flashcards
(126 cards)
1
Q
what is b cell receptor
A
antibody
2
Q
will not go from membrane bound to soluble BCR unless
A
you get infection
3
Q
specificity of epitope on BCR will not change when it is
A
soluble
4
Q
every antibody has how many antigen binding site
A
2
5
Q
what are two functional roles of b cell receptor
A
looks for antigen
secretes antibody
6
Q
immunoglobulin is
A
antibody
7
Q
Ab or Ig means
A
antibody
8
Q
neutralizing antibodies
A
bind microbe or toxin and block them from entry
9
Q
enhance innate cell function how
A
complement with antibody works better
10
Q
what is big difference b/w BCR on surface of receptor and the secreted form
A
there is transmembrane region that will not be present in secreted form of antibody
11
Q
BCR with transmembrane region will
A
stay on surface of b cell ,will be BCR
12
Q
what is basic structure of antibody
A
heavy chain and light chain
13
Q
antibody contains how many heavy and light chains
A
two identical light chains
two identical heavy chains
14
Q
variable region on antibody is involved in
A
binding to antigen
15
Q
constant region of antibody is involved in
A
mediating effector functions
16
Q
antigen binding site of antibody is combinatino of
A
variable region of heavy and light chain - so they will both contribute to antigen binding site
17
Q
resting b cell what will happen to most of them
A
they live until they die and they never find their “partner”
18
Q
mature naive b cell must express what on surface
A
must express both IgM and IgD on surface
19
Q
domain within light chain
A
constant and variable domain
20
Q
domain within heavy chain
A
3 or 4 constant domains and 1 variable domain
21
Q
Fab
A
portion that is antigen binding on antibody
22
Q
Fc
A
portion that is constant on antibody
23
Q
heavy chain has how many constant regions
A
3
24
Q
light chain has how many constant regions
A
1
25
each domain in antibody is
immunoglobulin domain
26
connecting Fc to Fab fragment
hinge region
27
hinge region
antibody is flexible, hinge connects Fc to Fab fragments
28
what does hinge flexibilty allow
antibody to bind antigen close together, far apart, moving
29
antibodies recognize almost how many antigenic determinants
infinite number
30
what portion recognizes the antigen
variable region
31
hypervariable region
determines specificity within variable domain
32
CDR stands for
complementarity determining region
33
what is magic number for CDR
3
34
there are how many hypervariable regions
3
35
how many hypervariable chains in heavy and light chain
3 in each
36
what region has the variablity in antibody
v region
37
what type of interaction does epitope have with zika virus
```
electrostatic forces
hydrogen bonds
van der waals forces
hydrophobic forces
NOT covalent
```
38
epitope does not have what kind of bond with antigen
no covalent bond
39
dissociation constant of 10^-12 is what affinity
very strong
40
dissociation constant of 10^-4 is what affinity
relatively weak but still have interaction
41
even though no covalent bond b/w antigen and antibody, it is still
a very strong bond b/c of all the forces
42
avidity
one single interaction of one antigen binding site with one epitope on
one that binds two is stronger than one that binds two.
avidity is combination of all the different interactions
43
once an antibody binds a particular pathogen what does it do
complement system more efficiently activated. C1 can bind directly to antibody molecule - the Fc region
44
IgM is a
pentimer
45
IgM has how many binding site
10
46
if a b cell is ready for action (to mature) it will have how many different antibodies on surface
2
| IgM and IgD
47
isotype switching only happens
after infection
48
describe clonal selection with IgM and IgG
our body already has antibodies for things that will help get rid of diseases we've never seen
49
What are the major classes of immunoglobulin
```
IgG
M
D
A
E
```
50
Fc is made up of
heavy chain
51
heavy chain designated by
greek letter
52
gamma heavy chain will make
IgG
53
u heavy chain will make
IgM
54
delta heavy chain makes
IgD
55
alpha heavy chain makes
IgA
56
epsilon heavy chain makes up
IgE
57
how many constant domains are in IgE
four
58
how many constant domains are in IgM
four
59
how many constant domains in IgA
three
60
what are the only immunoglobulins that have four constant regions
IgM
| IgE
61
what are first BCR
IgM
| IgD
62
breast milk has what immunoglobulin
IgA
63
IgE closely linked with/role in
parasite infections
| allergic diseases
64
what is main antibody in blood
IgG
65
IgG can cross
placenta
66
what is most abundant antibody
IgG
67
when you first get sick what is main antibody
IgM
68
IgM is a
pentamer
69
what is marker for B cell to be mature
IgM
70
what is only real function of IgD
present on surface of B cell
71
if IgD onsurface of B cell
B cell is mature - will respond if it encounters antigen
72
IgA is in
saliva, tears, breast milk, in secretions/mucosal surfaces
73
IgE
parasites
| allergic responses
74
what antibody for parasites and allergic resposnes
IgE
75
IgE is how much in blood
very low concentrations
76
what is biggest antibody
IgM
77
IgG and IgA have
subtypes
78
IgG types
1, 2, 3, 4
79
IgA types
1, 2
80
very very small amounts of
IgE
81
when is IgM pentamer
only when secreted. when it's on surface of B cell it is a monomer.
82
IgA is a (shape)
dimer
83
Besides IgM and IgA they are all
monomers
84
how is pentomer made
J chain
85
greek ltter for heavy chain for IgM
u (mu)
86
IgM can turn on what pathway
complement - classical pathway (only one to turn it on)
87
monomeric IgM has what kind of affinity
low
88
pentamerica IgM has what affinity
high avidity
89
80% of all antibodies in blood is
IgG
90
what is heavy chain of IgG
gamma
91
IgG can turn on what pathway
complement - classical pathway (needs two to turn it on)
92
memory b cells will have what in surface
mIgG
93
memory b cell is going to be mainly what antibody
IgG
94
FcRn is
brambell receptor or neonatal Fc Receptor
95
endothelial cells surrounding baby - how does IgG go to fetus
IgG attached to FcRB present in moms blood -endocytoesed through Fc Receptor and then released to baby
96
what type of protection is it when mom passes IgG to baby
passive protection - baby got premade IgG
97
what is another passive protection
antibody - like if you're bit by a snake
98
If IgA is in serum it is a
monomer
99
if IgA not in serum it is a
dimer
100
What holds together two IgA
J chain
101
Dimeric IgA connected by
J chain
102
IgA is main antibody secreted on
mucosal surfaces
103
how does IgA get to baby
poly-Lg receptor
| the receptor uses J chain to bind the dimer, endocytosed, the Poly-Ig goes with the IgA (different than the other IgG)
104
parasites and allergies, what antibody
IgE
105
what is receptor for IgE
Cell-bound via FcR
| epsiolon is the box
106
what is the affinity of IgE to Fc receptor
very high - when it binds it is staying
107
IgE receptors expressed on what cells with high affinity for binding to IgE
mast cells,eosinophils, basophils, langerhans cells
108
why id IgE very low in blood
it binds to mast cells then just stays bound to them
109
high affinity FcepsilonR binds IgE in the absence of
antigen
110
IgD found where
on mature b cell
111
IgD is co-expressed with
IgM on mature B cell
112
describe IgD and IgM and RNA splicing
IgD or IgM is decided based upon RNA splicing - so it's not until during the RNA stage that it decides on if it is going to be IgD or IgM
113
what does neutralize a virus mean
bind the virus in a spot so they can no longer infect the cells
114
what are biggest neutralizing antibodies
IgG IgM
115
what is main antibody for opsonization
IgG
116
what antibody for sensitization of mast cells
IgE
117
isotype
w/in a species. so humans all have IgG, IgM, etc. based on constant region
118
allotype
think allele. different alleles w/in a species. might get a different IgG from mom than you got from dad. might have slight differences in constant region
119
idiotype
porition that binds the antigen. b/w infections the antigen binding site will be different. the binding region that is different
120
CD3 present on
t cells
121
poly Ig is associated with
IgA
122
immunoglobulin superfamily
a lot of parts of the immune system that are related to each other, they have related genes, the domains are not only immunoglobulins
123
each variable region has how many hypervariable regions
3
124
hypervariable regions are also called
complementarity determining regions (CDR)
125
what does CDR stand for
complementary determining region
126
antigen binding site is composed of how many CDRs
3 light chain CDR
| 3 heavy chain CDR
