Lecture 6: Antigen Recognition by B Cell Receptors

Question 1

antibodies are made by

Answer 1

B cells

Question 2

Antibodies can be ____ or ______

Answer 2

secreted or seated on B cell surface (receptor)

Question 3

What is the difference between secreted antibodies and antibodies that act as B cell receptors?

Answer 3

Receptors have transmembrane domain. Secreted have hydrophilic tails

Question 4

The light chain can be either

Answer 4

kappa or lambda

Question 5

The ____ region engages effector function

Answer 5

constant region

Question 6

the variable region is the ______ site

Answer 6

antigen binding

Question 7

disulfide bonds are located between

Answer 7

CH3-CH3
CH1-CL
hinge (CH1, CH2)

Question 8

What make up the light chain?

Answer 8

VL and CL

Question 9

The ____ gives the antibody Flexibility

Answer 9

hinge

Question 10

Where is variability located on the antibody?

Answer 10

1st Ig domain

Question 11

V and C domains are constructed from two _______

Answer 11

beta sheets

Question 12

What about basic structure gives variability?

Answer 12

The beta sheet is longer on variable region

Question 13

What creates the globular Ig domain structure?

Answer 13

Ig fold (beta sandwich)

Question 14

_____ cuts the disulfide bond between CH1 and CH2

Answer 14

papain

Question 15

papain results in the following fragments:

Answer 15

Fab, Fab, Fc

Question 16

____ cleaves AFTER the amino-terminal side

Answer 16

pepsin

Question 17

pepsin results in fragments:

Answer 17

F(ab)2, pFc

Question 18

Antibodies can be joined together by a ________

Answer 18

flexible hinge

Question 19

Which two classes of antibodies do not have a hinge?

Answer 19

IgM, IgE

Question 20

Which Ig is most abundant?

Answer 20

IgG1

Question 21

___ is a pentamer

Answer 21

IgM

Question 22

____ is the first produced after an infection

Answer 22

IgM

Question 23

___ is secreted into mucosa

Answer 23

IgA

Question 24

____ exists as a dimer

Answer 24

IgA

Question 25

Which antibody classes activate classical complement system?

Answer 25

IgM, IgG3, IgG1, IgG2

Question 26

__ activates alternative complement pathway

Answer 26

IgA1

Question 27

___ binds to mast cells and basophils (allergic response)

Answer 27

IgE

Question 28

___ are transferred through placenta

Answer 28

IgG1m IgG2, IgG3, IgG4

Question 29

The _____ allows IgA and IgM to form polymers

Answer 29

J chain

Question 30

_________ increases the strength of the interaction between antigen - antibody

Answer 30

Ig polymerization

Question 31

IgG has high _____

Answer 31

affinity

Question 32

IgM (as a pentamer) has high _____

Answer 32

avidity

Question 33

IgM is ___ to respond and has not undergone ________

Answer 33

first; affinity maturation

Question 34

What are the three function of constant region?

Answer 34

1. binding to Fc receptors on immune cells 2. Active transport of antibodies (IgA:pIgR and IgG:FcRn) 3. activate complements

Question 35

The function of the antibody involves the (heavy/light/both) chain

Answer 35

heavy

Question 36

Both the heavy and light chain have three _____ regions and four ______ regions

Answer 36

hypervariable; framework

Question 37

there are ___ specific regions with high variability each on VH and VL

Answer 37

three

Question 38

_______ is not distributed equally on Fab

Answer 38

variability

Question 39

hypervariable regions lie in ________ of folded structure

Answer 39

discrete loops

Question 40

Antigen binding is facilitated by _______ regions

Answer 40

complementary-determining (CDR)

Question 41

Antibodies can bind in ____, ____, ____, or ______.

Answer 41

pocket, groove, extended surface, or protruding surface

Question 42

Antibodies can recognize _____ or ______ epitopes

Answer 42

linear or conformational

Question 43

_____ epitopes have a more broad response

Answer 43

linear

Question 44

_____ forces hold together antigen-antibody complex

Answer 44

noncovalent

Question 45

noncovalent forces examples

Answer 45

electrostatic forces, hydrogen bonds, van der waals, hydrophobic, cation-pi

Question 46

noncovalent forces can be interrupted by _____

Answer 46

salt concentration, pH change

Question 47

______ can elute antibodies in the lab via pH/salt disruption

Answer 47

affinity purification

Question 48

steric hindrance is the concept that

Answer 48

although pathogens have many different epitopes, the binding of one antibody will inhibit the binding of other antibodies that recognize different nearby epitopes due to conformational changes

Question 49

Which two species don't have light chains?

Answer 49

camel, shark

Question 50

How many CH regions do sharks have?

Answer 50

5