Chpt 4

Front 1

y-globulin fraction

Back 1

fraction of serum that contains antibodies, aka, immunoglobulins

Front 2

What are Antibodies Heterodimers of?

Back 2

4 chains; 2 light, 2 heavy.
This is the common structure of all antibodies.

Front 3

How many polypeptides in light chains?
Heavy?

Back 3

25000

50000

Front 4

How are light chains bound to heavy?

Back 4

-Disulfide bonds
Noncovalent linkages - salt , hydrogen, hydrophobic bonds.

Front 5

V Regions

Back 5

VL=light VH=heavy
The first 110 amino acids of the north amino end of chains;
Highly variable sequence.
-Responsible for the variability in antigen specificity between Abs.

Front 6

CDR

Back 6

Complementarity Determining Regions

On LIGHT and HEAVY chains

Antigen binding site on an Ab

Front 7

C region

Back 7

the constant region of antibodies.

-site of carbohydrate attachment

Front 8

papain

Back 8

digests antibody to produce 3 fragments.

2 identical: FAB - fragment, Ag binding
1 other: crystallizes during cold storage, so Fc

Front 9

Fc fragment

Back 9

the fragment produced by papain digestion that does not bind antigen and cyrstallizes

Front 10

multiple myeloma

Back 10

cancer of Ab-producing plasma cells
-normal plasma cells are endstage.
-clones in mmlma are unregulated- no stimulus, just proliferate.

Front 11

myeloma protein

Back 11

antibody from a myeloma patient - undistinguishable from normal Ab

Front 12

Bence-Jones proteins

Back 12

excess light chains excreted into urine by mmlma patinets

Front 13

amino terminal end: what type of region?

Carboxy terminal?

Back 13

Variable

Constant

Front 14

How many basic amino acid sequences of constant region of light chains?

Back 14

2.
Kappa and Lambda

Front 15

How many types of light chain constant regions are expressed in one Ab molecule?

Back 15

only 1. either lamda or kappa

Front 16

how many subtypes of Lambda in humans?

Back 16

4

Front 17

How many basic amino acid sequences encode the constant regions of heavy chains?

What's another name for them?

Back 17

5:
nu, delta, gamma, epsilon, alpha

ISOTYPE

Front 18

how many amino acids are delta, gamma, and alpha?

epsilon and nu?

Back 18

330

440

Front 19

u is what letter Ig?

Back 19

IgM

Front 20

delta

Back 20

D

Front 21

gamma

Back 21

G

Front 22

epsilon

Back 22

E

Front 23

alpha

Back 23

A

Front 24

Immunoglobin Domains

Back 24

2 types: Variable (Vl/Vh)
and Constant (Cl/Ch)

Light chains: 1 Vl, 1 Cl
Heavy chains: 1 Vh, 3 or 4 Ch

Front 25

Immunoglobulin fold

Back 25

characteristic fold of Ig domains; each domain contains 110 a.a., folded into antiparallel beta pleated sheets. Ig fold is a sandwich of the two sheets, with intramolecular disulfide bond holding them together. the cheese is hydrogen bonding.

Front 26

hypervariable regions

Back 26

highly variable in their amino acid primary structure - antigen binding sites of the antibodies - aka, complementarity determining regions

Front 27

framework regions

Back 27

the regions on variable domains (Vl/Vh) that are not highly variable (like CDR) but are more constant. the framework supporting the six CDR folds in the Fab fragment

Front 28

Purpose of Ch1 and C-light regions on Ab

Back 28

-to extend Fab arms of Ab molecule
-to increase overall diversity of CDR regions by increasing stability (gives a disulfide bond between H and L chains!)

Front 29

What type of Ig has the hinge region?

Back 29

IgG, IgD, IgA.

-makes the Fab arms more flexible.

Front 30

Since IgE and IgM don't have a hinge region, how do they make up for it?

Back 30

by having an extra Ch domain.

Front 31

What's different in mIg and sIg?

Back 31

the tail; carboxy terminal end is designed to fit the need.
hydrophilic - secreted

hydrophobic - memb. bound

Front 32

immature B cell expresses what Ig?

Back 32

only IgM.

Front 33

what is ADCC?

Back 33

Antibody dependent cell-mediated cytotoxicity. Fc region on Ab binds to Fc receptor on NK cells; the Ab actually acts as a receptor on the pathogenic cell, so NK cells can bind and kill the pathogenic cell.

Front 34

allotypic determinants

Back 34

subtle amino acid differences within a species.

e.g., mom develops antibody to fetus because fetus has paternal alleles.

Front 35

idiotypic determinants

Back 35

the variable regions on H and L chains actually act as antigens themselves.
individual determinents are idiotopes

idiotype = sum of idiotopes, which are spread out all over the variable region.

Front 36

polyclonal antibody response

Back 36

antigens that stimulate response have various epitopes, so bind/stimulate variety of Bcells, to proliferate and secrete a heterogenous variety of antibodies.

Front 37

monoclonal antibody response

Back 37

stimulation and production of only one type of clone of antibody and bcells. specific for one single epitope.

Front 38

hybridoma

Back 38

multiple myeloma cell fused to activated, antibody-producing b cell. has immortal life but produces monoclonal antibody. limitless supply!

Front 39

which two Ig classes have subsets, and what are they?

Back 39

IgG - g1, g2, g3, g4

IgA - a1, a2

Front 40

how many amino acids in Ig domain?
How many disulfide bonds, what type?

Back 40

100

2 disulfide bonds, intramolecular

Front 41

what is the building block of an Ab?

Back 41

immunoglobulin domain

Front 42

what is the J chain for?

Back 42

joining together 2 IgA molecules into a dimer. OR, joining 5 IgM molecules into a pentamer.

Front 43

which Ig's are MONOMERS

Back 43

IgG, IgE, IgD

Front 44

papain digestion gives

pepsin digestion gives

Mercaptoethanol reduction gives

Back 44

2 Fab and 1 Fc fragment

1 fragment = F(ab')2

2 H and 2 L chains

Front 45

plasmacytomas

Back 45

clones of malignant plasma cells

Front 46

isotype

Back 46

name for each of the 5 different Heavy chains

Front 47

definition of variability

Back 47

# of different amino acids at a given position/frequency of most common amino acid at given position

Front 48

Where are hypervariable regions?
Why called that?

Back 48

in the loop regions joining b-sheets in domains of vheavy and vlight chains.

Maximum variation in which amino acids occupy these sites is seen here.

Front 49

purpose of hinge region in which Abs

Back 49

IgG, IgD, IgA
Gives flexibility to segments

Front 50

Which mIg are expressed at which developmental stages?

Back 50

Early immature B cell: mIgM only
Later immature B cell: IgM/ mIgD - before antigen activation

Memory B cell: mIgM, mIgG, mIgA, mIgE.

Front 51

opsonization

Back 51

promotion of phagocytosis of antigens by macrophages and neutrophils

Front 52

cells that have FcR

Back 52

macrophages and neutrophils have Fc receptors

Front 53

Antibody-Mediated Effector Functions

Back 53

-opsonization
-complement activation
-ADCC
-Transcytosis

Front 54

effector functions of antibodies according to pinfen

Back 54

-precipitation/neutralization
-opsonization
-complement activation
-ADCC

Front 55

transcytosis

Back 55

movement of Ab across epithelial layer

Front 56

Which antibody subclass undergoes transcytosis?

Back 56

IgA

Front 57

what minor Ig subclass undergoes transcytosis

Back 57

IgM

Front 58

How Ab gets to mucosal surfaces of tracts, and to breast milk:

Back 58

transcytosis

Front 59

What Ig subclass crosses the placenta from Mother to Fetus

Back 59

IgG - most subclasses of it too (4)

Front 60

what type of immunization is transfer of Ig (which one?) from mother to fetus?

Back 60

Passive - IgG

Front 61

Most abundant Ig in Serum:
What does it do?
Structure?

Back 61

IgG

-Monomer
-Crosses placenta
-Mediates opsonization
-Activates Complement

Front 62

First Ig class to be secreted after primary antigen challenge:

-How is it expressed?

Back 62

IgM

-mIgM = monomer; sIgM = pentamer (which is secreted by plasma cells)

Function: activates Complement, minor role in mucosal secretions (with IgA)

Front 63

Predominant Ig in secretions:

structure:

in what secretions?

Back 63

IgA

monomer or multimer.

Breast milk, saliva, GI, GU, resp tracts

Front 64

Structure of IgA in
-serum

-secretions

Back 64

monomer or other


dimer or tetramer

Front 65

Ab responsible for allergy:

cells that express receptor for its Fc:

mechanism:

Back 65

IgE

basophils and mast cells express FcR

crosslinking of IgE by binding to multiple Antigens AND mast cells. Mast cells/basophils release histamine, inflammatory compounds (degranulation).

Front 66

Which Ig has no real function, but is the major membrane-bound Ig with IgM?

Back 66

IgD

Front 67

3 types of epitopes on antibodies:

Back 67

-isotypic
-idiotypic
-allotypic

Front 68

isotypic determinants

Back 68

CONSTANT REGION epitopes
-define each heavy-chain class/subclass
-define each light chain type/subtype

Front 69

isotypic determinants are foreign for whom?

Back 69

same/non-foreign within a species

foreign when injected into another species.

Front 70

allotypic determinants

Back 70

alleles that encode subtle a.a. differences so that even if two strains have IgG, you can't infuse from one mouse to the other because allotypic determinants will be foreign.

Front 71

significance of idiotype

Back 71

-antibody variable regions have distinct primary structure; this is recognized as foreign when injected in large amounts (monoclonal ab). then the recipient can raise anti-idiotypic antibodies.

Front 72

why secretory IgA, not just IgA?

Back 72

Secretory IgA is formed when IgA binds to polyIg receptor on basolateral membrane; a vesicle takes the complex across the epithelial cells and is released as Secretory IgA inside the lumen, to fight pathogens.

Front 73

immunoglobulin superfamily

Back 73

membrane proteins of which their genes were derived from a common primordial gene encoding the basic immunoglobulin fold domain structure.
some members:

TcR, MHCI and II, etc.

Front 74

common membrane feature of immunoglobulin superfamily:

Back 74

carboxy-terminal end of molecule is anchored in cell membrane

Front 75

making immunotoxins

Back 75

toxins normally have binding chains and thier inhibitory toxin chain. replace the binding chains with monoclonal antibody specific for cancer cell or whatever. it binds, delivers the toxin to the cell, it is released in the cytosol and does its toxic thing.

Front 76

what does differential processing do?

Back 76

determines whether Ig will be membranous or secreted. poly A signaling sequences point to places for excising rna. S is before M1 and M2. if cut is between S and M1, it will be secreted; if after m2, then membranous.

Front 77

How can IgM and IgD be expressed at the same time?

Back 77

there is no switch site for circular excision between the two gene segments. therefore they can both be transcribed/translated at the same time.

Front 78

chimeras

Back 78

molecular hybrids that link nucleotide sequences coding nonantibody proteins with sequences encoding antibody variable regions specific for ag.

Front 79

humanized antibody

Back 79

contains promotor, leader, and variable regions from mouse antibody gene, constant region exons from human.

less immunogenic when administ. to humans.

Front 80

chimeric immunotoxins

Back 80

Fc region is replaced with a toxin, so Fcreceptors on self cells don't recognize the antibody, but the variable region does, so the target cell is toxicated! like tumor cells..