ANTIBODIES Flashcards
Glycoproteins that recognize and bind to a particular antigen
with very high specificity
Antibodies
Antigen Binding sites
Epitope
(antibody binding site)
Paratope
What group of serum proteins does antibodies belong to?
Immunoglobulins
Where do immunoglobulins appear primarily?
Gamma band
At what band is Albumin found?
Alpha bond
At what bond is immunoglobulins found?
Gamma band
spleen is the primarily organ where the antigens
are destroyed
Reticular Endothelial system
postulated that certain cells had specific surface
receptors for antigen
Paul Ehrlich
• Occurred once antigen was introduced, it would select the cell
with proper receptor, combination would take place and
receptors would break off and enter the circulation as
antibody molecules
• New receptors would form in place of those broken off and
enter the circulation as antibody molecules
EHRLICH’S SIDE-CHAIN THEORY (SPECIFIC RECEPTOR)
Who postulates the Template theory?
Felix Haurowitz
• Antibody producing cells are capable of synthesizing a
generalized type of antibody and when contact with an
antigen occurs, the antigen serves as a mold or template and
alters protein synthesis so that antibody with specific fits is
made
• This now specific antibody enters the circulation, while the
antigen remains behind to direct further synthesis or
degradation to make more antibodies.
Template theory
Most accepted theory for antibody diversity. The key premise is that individual lymphocytes are
genetically programmed to produce one type of
immunoglobulin and that a specific antigen finds or selects
those particular cells capable of responding to it, causing it to proliferate.
Clonal selection
They independently supported
the idea of clonal selection process for antibody formation.
Niels Jerne and Mcfarlane Burnet
Which cell produces the antibody?
B-cells
How many polypeptide chains does an antibody contain?
4
They worked on Immunoglobulin G (IgG)
Gerald Edelman and Rodney Porter
A flexible Y-shaped molecule with four protein chains
Monomer
two sections at the end of Y’s arm. Contains also the antigen
binding sites (Fab) or the paratope. The Fab is identical on
the same antibody, but vary from one antibody to another.
Variable region
The number of binding sites = _________________?
the number of valences
• Stem of monomer and lower parts of Y arms
• Responsible for the type and antigen-antibody reaction that
occurs
• Constant region of heavy chain differs from one antibody
class to the other
• Structure serves as a basis for distinguishing the 5 different
classes: IgG, IgA, IgM, IgD and IgE
Constant region
• All of the antibodies have the same Fc region
• Mainly the one attached to the B cells or T cells
• For complement fixation, skin fixation and placental transfer
• No capability to bind the antibody
FC (FRAGMENT CONSTANT) REGION
FC region is for?
complement fixation, skin fixation and placental transfer
• First approximately 110 amino acids at the amino-terminal
end
• The remaining amino acids can typically be divided up into
two or three or more constant regions with very similar
constant regions with very similar sequences, designated CH1,
CH2, and CH3 (constant heavy chain 1,2,3)
Variable domain (heavy chain)
Constant regions of the H chain are unique to each class and
give each immunoglobulin
Constant region (heavy chain)
Refers to the heavy chain that determine the Ig class
Isotype
Minor variations of these sequences that are present in some individuals but not others
Allotype
• The aminoterminal ends of both L and H contain these
regions, which are essential to the formation of the antigen-
binding site
• variable portions of each chain are unique to a specific
antibody molecule.
Idiotype
Possess both constant and variable regions, it is the same for
all immunoglobulins
Light chain
Kappa: contains _____ of the Ig
Lambda: contains _____ of the Ig
65%
35%
How is Lambda and Kappa discovered?
produced by a malignant plasma cell from the urine of
Multiple Myeloma patients
At what temperature is bence jones proteins gonna precipitate?
60°C
Further heating of bence jones at 80 C, the precipitate will _______
Redissolve