SI LEC - Antibodies

Question 1

composition of AB

Answer 1

82-96% polypeptide

2-14% CHO

Question 2

Antibody molecule has 2 separable functions:

Answer 2

1) specific binding to antigen eliciting response

2) biological activity

Question 3

• Discovered that hyperimmunizing rabbits resulted in increased gamma
• Purification revealed antibody activity resided in this serum portion

Answer 3

kabat and tiselius

Question 4

Antibodies Are Made Up Of:

Answer 4

2 Light Chains (identical)

2 Heavy Chains (identical)

Question 5

Each Light Chain bound to Heavy Chain (L-H) by

Answer 5

Disulfide Bonds

Question 6

Heavy Chain bound to Heavy Chain (H-H) by

Answer 6

Disulfide Bonds

Question 7

First a/a of amino terminal vary for both H and L Chains (Variable Region)

Answer 7

__

Question 8

First 100 a/a of amino terminal vary for both H and L Chains (__ Region)

Answer 8

Variable

Question 9

: Ag-binding site

Answer 9

CDR (Complementarity Determining Regions)

Question 10

The folded domains of the H chain line up w/ the L chains forming an ___

Answer 10

immunoglobulin fold/barrel

Question 11

Antigen is captured w/in barrel by binding to a small number of amino acids at strategic locations known as

Answer 11

hypervariable regions.

Question 12

Immunoglobulins (with possible exception of IgM & IgE) contain hinge between

Answer 12

CH1 & CH2

Question 13

Is there homology between AA sequence of hinge & heavy chains

Answer 13

None

Question 14

residues in hinge region

Answer 14

proline and cysteine

Question 15

hinge region residue involved in formation of interchain disulfide bonds

Answer 15

Cysteine

Question 16

hinge region residue
prevents folding in a globular structure, allowing flexibility between
two Fab arms of the Y-shaped antibody; ;

Answer 16

Proline

Question 17

hinge region residue
allows open & close to accommodate
binding to two epitopes

Answer 17

Proline

Question 18

hinge region residue
because it is open, it can be cleaved by proteases
(e.g. papain) to generate the Fab & Fc fragments

Answer 18

Proline

Question 19

: centered on using analytic ultracentrifuge on the basis of MW

Answer 19

Gerald Edelman

Question 20

: worked on the use of papain to cleave IgG into 3 pcs.

Answer 20

Rodney Porter

Question 21

Used 7M urea to unfold IgG : exposed the sulhydryl bonds

Answer 21

Gerald Edelman

Question 22

Gerald Edelman Used ___ to unfold IgG : exposed the sulhydryl bonds

Answer 22

7M urea

Question 23

unfolding IgG exposed __

Answer 23

sulhydryl bonds

Question 24

Treatment with mercaptoethanol yielded

Answer 24

Treatment with mercaptoethanol = 4 chains:

Question 25

breaks S-S bonds

Answer 25

mercaptoethanol

Question 26

used PEPSIN :

Answer 26

Alfred Nansoff

Question 27

Treatment with proteolytic enzyme, papain,

Answer 27

2 capable of ag rxn (fragment antigen binding)

1 could be crystallized (fragment- crystallizable)

Question 28

specifically bind antigen,
can’t precipitate
univalent/one binding site each,
identical to each other

Answer 28

Fab

Question 29

: crystallizable (thus homogenous) , can’t bind ag,
responsible for biological activity of molecule
after Ag bound to Fab portions

Answer 29

Fc

Question 30

This proteolytic enzyme was found to cleave IgG at the carboxy-terminal side of the interchain disulfide bonds, yielding one single fragment (Fc) and antigen binding fragment called F(ab)2.

Answer 30

pepsin

Question 31

found in urine of patients with MM

Answer 31

Bence Jones Protein :

Question 32

BJP: peculiar behavior ppt at __

Answer 32

60C,

Question 33

BJP: peculiar behavior

reappears upon ___

Answer 33

cooling

Question 34

BJP: dissolves at __

Answer 34

80C

Question 35

Two main types of LC

Answer 35

Lambda

Kappa

Question 36

First 110 amino acids at terminus : constant or variable?

Answer 36

highly Variable (V)

Question 37

First 110 amino acids at terminus of HEAVY CHAINS: highly Variable (V)

Answer 37

110 AA

Question 38

Remaining aa can typically be divided up to 3 or more constant regions

WHAT CHAIN

Answer 38

HEAVY

Question 39

Immunoglobulin variations 
class of Ig, unique aa sequence that is common to all Ig molecules of a given class in a given species

Answer 39

Isotype

Question 40

Immunoglobulin variations
genetic difference, depends on existence of allelic forms of the Ig , result of different forms of the same gene, involve changes of 1-3 AA in constant region

Answer 40

Allotype

Question 41

Immunoglobulin variations

one of several thousand Ig, each of which directed toward specific epitope

Answer 41

Idiotype