Immunoglobulins structure and isotypes

Question 1

Function of constant region

Answer 1

Responsible for effector fucntions.

Question 2

Function of variable region

Answer 2

Antigen binding site.

Question 3

Papain in what divides the Antigen?

Answer 3

In the Fc and the 2 Fab.

Question 4

Pepsin in what divides the Antigen?

Answer 4

In 1 units of F(ab’)2.

Question 5

Which type of structures have the domains in the antigen?

Answer 5

Beta-structures which are linked by loops (disulfide bonds).

Question 6

How are called the three regions in the variable domain where a high variability is observed?

Answer 6

Hypervariable regions or complementary determing regions.

Question 7

In what part of the variable region does the antigen bind?

Answer 7

In CDRs (Complementary determining regions).

Question 8

Which is the scaffold (andamio) of CDRs?

Answer 8

The framework regions

No Antigen interaction.

Question 9

What’s an idiotype?

Answer 9

Is the structure generated by the 6 CDRs of the antibody.

Question 10

What does the idiotype determines?

Answer 10

It determines the Ag especificity.

We can have the same type of An (IgG) but with different affinities.

Question 11

Which region determines the flexibility of the Antibody?

Answer 11

The Hinge (bisagra) region.

Located ar the heavy chains.

Question 12

Which Aa confere flexibility?

Answer 12

Prolines

Question 13

Which Aa favor heavy chain dimerization?

Answer 13

Cysteine

Through the formation of disulfide bonds.

Question 14

Which fucntion have the An that posses an hydrophobic tail?

Answer 14

Receptor Function

Question 15

Which Ag have 4 constant domains in their heavy chains?

Answer 15

IgE and IgM

Question 16

By which chains are the isotypes determined?

Answer 16

By heavy chains.

Question 17

Why does An coating of pathogens promote phagocytocis?

Answer 17

Through Opsinization.

Macrophages and neutrophils have Fc receptors.

Receptros can bind to the constant region of most subclasses of IgG.

Question 18

Which types of Ig activate the complement cascade?

Answer 18

IgM and most subclasses of IgG.

Question 19

Which is the first An produced?

Answer 19

IgM

Question 20

Which An protects the fetus and neonates?

Answer 20

IgG

Question 22

Which IgG subclass inactivates complement, and which is the most active?

Answer 22

IgG 3 activates
IgG 4 inactivates

Question 23

Which Ig are important for neutralization?

Answer 23

IgG and IgA

Question 24

Which Ig are expressed on mature B cells?

Answer 24

IgD and IgM