Immunoglobulines

Question 1

what other names do immunoglobulines receive?

Answer 1

gammaglobulines or antibodies

Question 2

which cells produce immunoglobulines?

Answer 2

plasma cells

Question 3

5 main classes of antibodies

Answer 3

IgG, IgA, IgM, IgE, IgD

Question 4

what is a BCR?

Answer 4

B-Cell Receptor, membrane bound immunoglobulines

Question 5

what is an antibody?

Answer 5

secreted immunoglobulines, proteins circulating in blood

Question 6

name the parts of the basic structure of the antibody

Answer 6

• heavy chains
• light chains
• disulphide bonds
• Hinge region
• FC region
• short carbohydrate chains

Question 7

what are disulphide bonds for?

Answer 7

they connect the H chain with the L chain

Question 8

what is the function of the Hinge region?

Answer 8

2 disulphide bonds in the mid-region that give flexibility to the antibody

Question 9

what is the FC region?

Answer 9

part of the andibody (the stem) which is recognized by the immune system cells

Question 10

what are the short carbohydrate chains for?

Answer 10

(attached to each H chain) they are important for solubility for transportation in blood

Question 11

molecular weight of L chains

Answer 11

25 kDa (kilodaltons)

Question 12

amount of aminoacids of L chains

Answer 12

220 aminoacids

Question 13

types of L chains

Answer 13

• lambda (encoded in chromosome 22 - 40%)
• kappa (enconded in chromosome 2 - 60%)

Question 14

molecular weight of H chains

Answer 14

50-70 kDa (kilodaltons)

Question 15

amount of aminoacids of H chains

Answer 15

440 aminoacids

Question 16

where are all types of H chains encoded in?

Answer 16

chromosome 14

Question 17

what is the variable region?

Answer 17

the fisrt 110 aminoacids of both L and H chains can be variable; this region interacts with the epitopes

Question 18

what do Variable L chain + Variable H chain form?

Answer 18

antigen binding site

Question 19

what is the name of the variable aminoacid sequences?

Answer 19

hypervariable regions or complimentarity determining regions (CDR)

Question 20

what is the function of the CDRs?

Answer 20

they have direct contact with the epitope

Question 21

what are the framework residues (FR)?

Answer 21

intervening sequences between the CDRs, they don’t interact with epitopes

Question 22

what is the constant region?

Answer 22

region where aminoacids have little or no variability at all

Question 23

IgG

Answer 23

• most common class
• 4 subtypes
• the only one capable of crossing the placenta (provides immunity to fetus)
• secreted into mother’s milk

Question 24

IgA

Answer 24

• found in tears, saliva, respiratory and intestinal secretions, colostrum
• produced by B-cells located in mucous membranes
• most synthesized immunoglobuline

Question 25

IgM

Answer 25

• most common present as the antigen receptor on B-cell surface
• 10 antigen binding sites (5 Y-shaped units)
• effective at attacking bacteria
• aglutinate together bacteria to be easier phagocyted

Question 26

IgE

Answer 26

• low concentrations
• each H chain has an extra constant domain
• the extra CH4 allows binding to basophils and mast cells
• involved in allergic reactions
• protect agains parasite infections

Question 27

IgD

Answer 27

• function as BCRs
• low concentrations in blood
• not clear function