ANTIBODY AND ANTIGEN

Group 3:M. Yusron Hasani (105090100111037)A. Muammar Kadafi (115090101111012)Nira Meirita W. (115090100111017)Putri Indisari (115090107111021)

JURUSAN BIOLOGIFAKULTAS MATEMATIKA DAN ILMU

PENGETAHUAN ALAMUNIVERSITAS BRAWIJAYA

MALANG2013

ANTIGENSubstance that stimulates the production of

antibodies and can be recognised by a B cell receptor or antibody, or a T cell receptor.

Protein, polisakarida or other molecule Part of the antigen which comes into contact

with the antigen receptor is called the epitope or antigenic determinant

Epitope, or antigenic determinant, is a small, specific portion of an antigen recognized by the immune system such as antibodies. A single antigen usually has several different epitopes. The region on an antibody which recognizes the epitope is called a paratope. Antibodies fit precisely and bind to specific epitopes.

ANTIGEN STRUCTURE

linear or sequential epitope is an epitope that is recognized by antibodies by its linear sequence of amino acids, or primary structure

Conformational epitope that has a specific three-dimensional shape and its protein structure. In contrast, most antibodies recognize this epitope

Types of epitopes

Major histocompatibility Complex

What are the MHC molecules? MHC:

Antibody General Structure

Immunoglobulin Fragmentation

Kinds of Immunoglobulin

The binding between antibodies and antigens has high specificity and affinity resulting from various structural and energetic aspects.

Is a non covalent bond ( similar mechanism as lock and key on enzyme and a substrate )

Happens because the molecular structure of an antibody typical

Antigen-Antibody Binding

Interaction Antigen-Antibody

Pre-natal used IgG as antibody

Post-natal used IgA from colostrum as antibody

Immune system on pre-post natal

Response to the first exposure to antigen called primary immune response, mediated by lympocytes, called naïve lympocytes

Subsequent encounters with the same antigen lead to responses, called secondary imune response

First exposure to antigen stimulate primary imun responses signalling by IgM few days after exposing.

Time between exposure and appearance of IgM antigen called the lag phase

In serum, IgG start to be detected 6-7 days after exposure

When second exposure to antigen occurs, secondary immune response in which IgM and IgG levels increased rapidly with a short lag phase

IgM levels did not exceed the peak levels of the primary response, but IgG levels rise much higher and lasts longer

Much better response faster on secondary immune response

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