Antibodies Flashcards
Antibodies is aka
immunoglobulins
it is the end product of antigen stimulation and
differentiation of B cells
Antibodies
Glycoproteins found in the serum portion of the
blood
IMMUNOGLOBULINS
IMMUNOGLOBULINS Constitute approximately _____% of _____ in healthy individuals
20%
plasma proteins
Constitute approximately 20% of plasma proteins
in healthy individuals
IMMUNOGLOBULINS
IMMUNOGLOBULINS is composed of ___ to ____ polypeptide and ___ to ____ carbohydrate
86% to 98%
2% to 14%
IMMUNOGLOBULINS Composed of 86% to 98% ____ and 2% to
14% _____
polypeptide
carbohydrate
Composed of 86% to 98% polypeptide and 2% to
14% carbohydrate
IMMUNOGLOBULINS
● Play an essential role in antigen recognition and
in biological activities related to the immune
response such as opsonization and complement
activation
IMMUNOGLOBULINS
IMMUNOGLOBULINS is divided into ___ major classes on the basis of a part of the molecule called the ‘_______’
five
heavy chain
What are the five major classes of immunoglobulins
→ IgG – γ
→ IgM – μ
→ IgA – α
→ IgD – δ
→ IgE – ε
STRUCTURE OF IMMUNOGLOBULINS
Tetrapeptide
STRUCTURE OF IMMUNOGLOBULINS is tetrapeptide as elucidated by _____ and ___
Gerald Edelman and
Rodney Porter
STRUCTURE OF IMMUNOGLOBULINS Consists of two large chains called _____ or ____ and two smaller chains called ____ or ____
heavy or H chains
light or L chains
T/F The two large chains in the structure of immunoglobulin is called heavy or H chain
T
T/F The two smaller chains in the structure of immunoglobulin is called light or L chains
t
STRUCTURE OF IMMUNOGLOBULINS
Each chain has a ________ (unique to
each specific antibody) and one or more ______
single variable region
constant regions
the single variable region in the structure of immunoglobulin is unique to each ______
specific antibody
STRUCTURE OF IMMUNOGLOBULINS
Chains are held together by _________ and _________
non-covalent forces
disulfide interchain bridges
Cleaved IgG into 3 pieces
Papain Digestion
Papain Digestion Cleaved IgG into ___ pieces
3
Fc fragment
Papain Digestion
Fc in Fc fragment stands for
fragment crystallizable
Fc fragment in Papain Digestion is Spontaneously crystallized at _____
4˚C
Spontaneously crystallized at 4˚C
Fc fragment
Has no antigen binding ability
Fc fragment
Important in the effector functions of Ig
molecules (opsonization and complement
fixation)
Fc fragment
2 identical Fab fragments
Papain Digestion
Fab in 2 identical Fab fragments in Papain digestion stands for
Fragment Antigen Binding
Have antigen-binding capacity
2 identical Fab fragments
Consists of one L chain and one-half of an H
chain held together by disulfide bonding
2 identical Fab fragments
2 identical Fab fragments consists of one _____ and one-half of an ____ held together by ______
L chain
H chain
disulfide bonding
Cleaved IgG at the carboxy-terminal side of the
interchain double bonds
Pepsin Digestion
Pepsin Digestion Cleaved ______ at the ____ side of the
_______
IgG
carboxy-terminal
interchain double bonds
F(ab’)2 and Fc
Pepsin Digestion
T/F: In Pepsin Digestion, F(ab’)2 and Fc is similar to Fc except that it
disintegrated into several larger pieces
F; SMALLER pieces
2 types of Light Chains
→ Kappa chains
→ Lambda chains
Each contains between 200-220 amino acids
Light Chains
Light Chains each contains between _______
with the same sequence from _________ (the amino terminus is position ______)
200-220 amino acids;
111 onwards;
number 1
it is the region in light chain
with the same amino acid sequence
Constant region
Light Chains:
amino-terminal end
Variable region
In LIGHT CHAINS;
___ of ____ are kappa chains because they
are coded for first in ____ of genes
coding for _____
60%
L chains
DNA transcription
antibody molecules
The difference lies in the amino acid substitutions
at a few locations along the chain
Light Chains
No functional differences between the two types
Light Chains
Both are found in all five classes of
immunoglobulins, but only one type is present in a
given molecule
Light chains
With variable and constant regions
Heavy Chain
Region in heavy chains
location of the first approx. 110 amino acids at the amino-terminal end
Variable region
The Variable region in Heavy chains
location of the first approx. ____
amino acids at the _____
110
amino-terminal end
location of the remaining
amino acids in the HEAVY CHAINS
Constant region
can be divided into 3 or 4 constant
regions with very similar sequences: CH1, CH2,
and CH3
Constant region
The constant region in HEAVY CHAIN can be divided into ____ constant regions with very similar sequences: ___, _____,
and ____
3 or 4
CH1, CH2, and CH3
Unique to each class and give each
immunoglobulin type its name:
Heavy Chain
IgG has an ____ chain
γ
IgM has a ___ chain
μ
IgA has a ___ chain
α
IgD has a ____ chain
δ
IgE an ___ chain
ε
A unique amino acid sequence that is common to
all immunoglobulin molecules of a given class in a
given species
Isotype
Isotype is determined by the _____
heavy-chain constant region
What are the five antibody isotypes that each
have a unique heavy-chain constant region
IgM, IgD, IgG, IgE, and IgA
Minor variations in isotype
Allotypes
occur in the four IgG subclasses, in one
IgA subclass, and in the κ L chain
Allotypes
Allotypes occur in the ____ ____ subclasses, in ___
___ subclass, and in the ___ ____ ___
four IgG;
one IgA;
κ L chain
Variable portions of each chain that are unique to
a specific antibody molecule
Idiotype
Amino-terminal ends of both L and H chains,
serve as the antigen-recognition unit
Idiotype
Idiotype serve as
antigen-recognition unit
The segment of H chain located between the CH1
and CH2 regions
Hinge Region
Has a high content of proline and hydrophobic
residues
Hinge Region
T/F Gamma, delta, and alpha all have a hinge region,
but mu and epsilon chains do not
T
all have a hinge region
Gamma, delta, and alpha
HINGE REGION:
All types of immunoglobulins contain a
____ portion, which is localized between
the ___ domains of the two _____
carbohydrate
CH2
H chains
Allows for flexibility and assists in effector
functions including initiations of the complement
cascade and binding to cells with specific
receptors for the Fc portion of the molecule
Proline
Proline Allows for ____ and assists in effector
functions including ___ of the complement
cascade and _____ to cells with _____ for the ____ portion of the molecule
flexibility;
initiations;
binding;
specific receptors;
Fc
lets the two antigen-binding sites operate
independently and engage in an angular motion
relative to each other and to the FC stem
Proline
Increases the solubility of immunoglobulin
Carbohydrates
Provides protection against degradation
Carbohydrates
Enhances functional activity of the FC domains
Carbohydrates
Predominant immunoglobulin in humans
Immunoglobulin G (IgG)
70 – 75% of total serum immunoglobulins
Immunoglobulin G (IgG)
Immunoglobulin G (IgG) is _____ of total ____ immunoglobulins
70 – 75%
serum
Half life of IgG
: 23 days
Give the four major subclasses of IgG
→ IgG1
→ IgG2
→ IgG3
→ IgG4
IgG1 percent distribution
66%
IgG2 percent distribution
23%
IgG3 percent distribution
7%
IgG4 percent distribution
4%
