This document summarizes the main types of antibodies (immunoglobulins). It discusses the structure of antibodies, which consist of two heavy chains and two light chains arranged in a Y-shape. Antibodies are classified based on their heavy chain type, with the main types being IgG, IgA, IgM, IgE, and IgD. Each antibody type serves a different function, such as IgG being the most common antibody in serum and IgA providing defense in external secretions like breast milk. In summary, the document outlines the structure of antibodies and classifies the main antibody types while briefly describing their functions in the immune system.

1. Presented by :- Jatin Anand
IMMUNOGLOBULINS
(Also called antibodies)

2. CONTENTS
01
02
04
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INTRODUCTION OF ANTIBODY
STRUCTURE OF ANTIBODY
CLASSIFIED OF ANTIBODY
EXPLAINED ALL TYPES
ANTIBODY

3. ● Antibody is large Y- shaped protein
(Glycoprotein), produced by plasma cells.
● Antibody have the capability to bind with the
epitops of an antigen.
● Its used by Immune system to Identified &
neutralized the foreign particals (pathogens),such as
bacteria and viruses.
Introduction of Antibody

4. ● Antibody contribute to immunity in three ways :
1) Preventing pathogens from entering or damaging
cells by binding to them neutralization.
2) Stimulating removal of pathogens by
macrophages,phagocytic cells & other cells by coating
the pathogens (opsonization).
3) Triggering destruction of pathogen such as the
complement pathway.

6. Structure of Antibody

7. ● All immunoglobulin has a basic structure that
composed of four polypeptide chains:
Two identical heavy chains & Two identical light
chains.
● Each light chains contains about 220 Amino acids &
has molecular weight 25,000 Dalton.
● Each heavy chains contains about 440 Amino acids
& has molecular weight ~50,000 to 70,000 Dalton.

8. ● The heavy chains are structurally distinct for each
Immunoglobulin class & subclass.
● Both Light and heavy chains contains two different
regions: Constant region & variable region.
Variable region:- The amino acid sequences of this
region can vary from cell to cell from time to time.
Constant region:- The amino acid sequences of this
region can different in all classes of immunoglobulin.

9. ● The four chains are arranged in the form of Y shape
with a hinge region.
Hinge region :-
* It is allowed the antibody molecule to be flexible,
adjusting to the different special arrangement of
epitops of antigens.
* The IgG , IgA or IgD of heavy chain contain the
hinge region . which is rich in proline cysteine amino
acid residues.

10. ● The stalk of the Y region is termed as crystalisable
fragment or fc- receptor.
Fab(Fragments antigen binding)region:-
* It is help of specifically intract with antigens
(epitops).
Fc (Fragment crstallizable)region:-
* It is help of intract with the cell surface receptors of
our immune cells.

11. * For eg :- B-cell have a B-cell receptor with the help
of this Fc region antibody can easily bind with that
receptor by this functions.
● Light chain may be either of two distinct forms
called Kappa and Lambda . these can be
distinguished by the amino acid sequences of the
constant portion of the chain .

12. ● In human beings, the constant region of all chains
are identical and each antibody molecule produced
by B-cell will contains either kappa and lambda light
chain but never both .
● The light chain variable domain contains
hypervariable regions or complementary determine
regions (CDRs) that differ in amino acids sequences
more frequently than rest of the variable regions.

13. Classified on the basis of Heavy chain
IgM
IgG
morel gypsum dolor
IgA
IgE
IgD
IgG :-
Gamma heavy
chains.
IgA :-
Alpha heavy chains
IgM :-
Mu heavy chains.
IgE :-
Epsilon heavy
chains.
IgD :-
Delta heavy chains.

14. The order of the human serum in found
concentration of various immunoglobulins
IgG - 80%
IgA - 10 to 15%
IgM - 5 to 10%
IgD - 0.2%
IgE - 0.1%

15. Immunoglobulin G (IgG) :-
● Ig-G is the most abundant class of immunoglobulin,
which consists about 80% of the total serum
immunoglobulin. Location: blood, lymph & intestines.
● It consist of Two heavy chain - gamma type &Two light
chain - kappa/lambda type.
● There are mainly four subclasses in human Ig-
G,distinguished by differences in their Y chain constant
region Amino sequences & number according to their
decreasing concentration.

16. IgG1 < IgG2 < IgG3 < IgG4.
● The structural characterstics that distinguished, these
subclasses from another are number & positions of
interdisulfide bond between their heavy chains.
● The sub amino acid sequences differ from between
subclasses of IgG ,which affects the biological activities of
the molecules.
● IgG1,IgG3 & IgG4 can pass through the placenta,
enabling the mother to transfer her immunity to the
fetus.

17. ● IgG3 is the most effective complement activator
,followed by IgG1,IgG2 is less efficient & IgG4 is not
able to activate complement at all .
● IgG1 and IgG3 bind with high affinity to Fc receptors
on phagocytic cells and thus mediate opsonization.
● IgG4 has an intermediate affinity for Fc receptors,
IgG2 has an extremely low affinity.

18. Immunoglobulin A (IgA) :-
● IgA constitutes only 10-15% of the total
immunoglobulin in serum.
Location: epithelial cells
● It is predominant immunoglobulin class in external
secreation such as breast milk, saliva, tears, mucus of
the bronchial, genitourinary & digestive tract.
● The IgA of external secretions, called secretory IgA.

19. ● IgA is dimer form structure i.e. the two
subunit of immunoglobulin are joined by j-
chain. and another linking molecules that
facilitate the dimerisation is the polypeptide
chain called as secretory component.
● IgA provides first line of defense to new
born as they feed on mother milk.
● It is also neutralize various pathogens
carried with food in gastrointestinal tract.

20. Immunoglobulin M (IgM) :-
● IgM constitutes about 5-10%
of the total serum
immunoglobulin, with an
average concentration of
1.5mg/ml.
Location : blood and lymph.

21. ● Monomaric IgM is expressed as membrane
bound antibody over B-cell but once secreated
or released from the surface of B-cell, it forms a
pentameric structure of antibody connected
through disulfide linkage and j-chain.
● The heavy chain are of mu- type & light chain
can be of kappa or lambda type.

22. ● It provide the primary response against antigens.
● Theoretically, pentameric IgM can bind to 10
antigens at a time but practically, it can only bind to
5-6 antigens simultaneously due to the larger size of
some antigens.
● IgM is the first class immunoglobulin produced in a
primary response to an antigens & it is also the first
immunoglobulin to be synthesized by the Neonate (a
new born child).

23. Immunoglobulin D (IgD) :-
● It is constitutes for about 0.2% of the total
immunoglobulin in serum.
Location : blood, lymph & B-cell surface BCR(B-
cell receptor).
● IgD together with IgM, is the major membrane
bound immunoglobulin expressed by mature B-
cell & it is role in physiology is under investigation
(functions is not found).

24. ● The structure of IgD is similar to IgG & IgE,except it
is heavy chain that is made up of delta type.

25. Immunoglobulin E (IgE) :-
● It is found in very low concentration in serum(0.1%).
Location : blood on surface of mast cells &basophils.
● IgE antibody mediates the hypersensitivity reaction
that are responsible for the symptoms of allergy.

26. ● The secretion of IgE can bind to inflammation or
sometimes asthma.
● The structure of IgE is similar to IgG except it is
heavy chain that is made up of epsilon type.

28. THANK YOU
Presented by :- Jatin anand