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Newsletter Title
Antibodies
by Tharika Raveendraraja
This article helps you to understand the basic knowledge antibodies and why it is important,
basic structure and function+ We are generally know antibodies are help to prevent the microbes which are pathogen to human body and some unwanted substance (normally called
antigen), they are in human blood, once enter the microbes to the human body antibody will
kill them+ This is the basic idea of as we generally know+ In this article we are discussing little
more of these antibodies+
Other word of antibodies called immunoglobulin+ Antibodies are the protein molecule, composed of fore polypeptide chains they have 2 idenFigure 1 An antibody is Y-shaped and has two identical
binding sites for its antigen, one on each arm of the Y.
(A) Schematic drawing of a typical antibody molecule.
The protein is composed of four polypeptide chains
(two identical heavy chains and two identical and
smaller light chains) held together by disulfide bonds.
Each chain is made up of several different domains,
here shaded either blue or gray. The antigen-binding
site is formed where a heavy-chain variable domain
(VH) and a light-chain variable domain (VL) come close
together. These are the domains that differ most in
their sequence and structure in different antibodies.
(B) Ribbon drawing of a single light chain showing the
parts of the VL domain most closely involved in binding to the antigen in red; these contribute half of the
fingerlike loops that fold around each of the antigen
molecules in (A). Essential Cell Biology, Second Edition, published by Garland Science in 200 by Bruce
Albert's, Dennis Bray, Alexander Johnson, Julian Lewis,
Martin Raff, Keith Roberts, and Peter Walter)
tical heavy chains and 2 identical light chains both are contains variable regions and constant
region+ The variable parts of antibody help to binds antigen+ The constant region of antibody
give 5 types of antibody classes IgM, IgE,
IgG, IgA, IgD+
The four chains are given “Y” shapes
of antibodies+ The picture given below will
explain how they are arranged and form “Y”
shape+
Light chain made up of one variable (v) and
one constant (c) area, heavy chain made up
of one v and 3 or 4 c area+ Each area folds
into a 3 dimensional shape, which is called
immunoglobulin (Ig) domain+ This Ig domain
consists of 2 beta sheet bind together disulfide bridge+ The ig domain present not only
the antibody they present in other human pro- Figure 2 -antibody production. The B-cell expresses an activation receptor on its surface (CD40) that
tein molecules they are involved in sensing
signals from the environment and from other