Immunoglobulin structure, function and organisation Flashcards
Immunoglobulins are ______ molecules that are produced by ________ in response to the presence of _________ in a living tissue.
Glycoprotein
plasma cells
an immunogen
An Immunogen is a substance usually a ___ that can elicit ___________
protein
an immunologic reaction.
A hapten is a (small or large?) molecule that can _____________ only when ___________
Small
elicit an immune response
attached to a carrier protein
Valence of an immunoglobulin : Number of _________________
Most are _________
.
antigen binding sites.
bivalent
Functions of Immunonoglobulins
Binding to__________ (and self antigens in some disease states causing _______ disorders
_________ fixation
Enhancement of _______
Release of specific __________.
foreign antigens; auto immune
Complement
phagocytosis
cytochemicals
Immunoglobulins (Ig) are glycoproteins made up of _______ and ________ polypeptide chains.
light (L) and heavy(H)
The simplest antibody molecule has a ____ shape and consists of ____ polypeptide chains:
_____ Heavy chains and ____ Light chains.
The chains are linked by _____ bonds.
Y
four
Two; Two
disulfide
The Disulfide bonds are only Inter-chain bonds
T/F
F
Both – Inter-chain and – Intra-chain
Immunoglobulin Structure
________ and ________ Regions
_______ Region
Variable & Constant
Hinge
Heavy chains are the same for each Of the five Ig classes or isotypes
T/F
F
Heavy chains are distinct for each Of the five Ig classes or isotypes
the five Ig classes or isotypes are designated :____,______ ,_____,—— ,____ for the respective classes
of Ig, namely Ig__, Ig__, Ig__, Ig___ and Ig__
γ, α, μ, δ, ε
G, A, M , D, E
Human Immunoglobulin Classes
IgG –______ heavy chains
IgM -_____ heavy chains
IgA - ______ heavy chains
IgD - ______ heavy chains
IgE - ______ heavy chains
Gamma
Mu
Alpha
Delta
Epsilon
Light chains are one of two types designated ___ and ___ and only
one type is found in each Immunoglobulin.
κ and λ
Human Immunoglobulin Light Chain Types
______ (K)
_______ (λ)
Kappa
Lambda
L and H chains are subdivided into ______ and ______ regions.
The regions are composed of ______-dimensionally folded, repeating segments called ______.
variable and constant
three
domains
Light chain consists of ____ variable (VL) and ____ constant (CL) domain.
Most H chains consist of ____ variable (VH) and ______ constant(CH) domains.
one; one
one; three
IgG have______ CH Domains
IgA have ______ CH Domains
IgM have ______ CH Domains
IgE have ______ CH Domains
three
Three
Four
Four
Variable Regions , AKA ___________
Constant regions , AKA __________
Antigen binding sites
Effector function
Immunoglobulin structure
Each light chain is connected to a heavy chain by _________ and the two heavy chains are connected by ___________
A disulfide bond
two disulfide bonds.
Immunoglobulin structure
Antigen binding and effector domains are separated by a ________.
hinge region
Immunoglobulin structure
The hinge region allows the __________ domains to ______, enabling them to ________ that are separated by varying __________.
two antigen binding
move
bind antigens
distances
Variable (V) and Constant (C) Regions
- V-region lies in ______ portion of molecule
- V-region shows (little or wide?) variation in amino a. sequences which is Responsible for the _________
terminal
Wide
antigen binding.
Variable (V) and Constant (C) Regions
- C-region lies in _______ or ______ portion of molecule
- C-region shows ________ amino acid sequence
- It is responsible for ______ functions
carboxyl or terminal
an unvarying
biologic
The variable regions are responsible for _________ , while the constant
regions are responsible for various ________ such as ________and ———————-
antigen binding
biologic functions
complement activation
binding to cell surface receptors.
Immunoglobulin Fragments: Structure/Function Relationships
Fab
–__________
Fc
– _________
Ag binding
Effector functions
Immunoglobulin Fragments: Structure/Function Relationships
F____
– Ag binding
F____
– Effector functions
Fab
Fc
Immunoglobulin Classes
I. IgG
Structure: ______
Percentage serum antibodies: ____% Location: Blood, lymph, intestine
Half-life in serum:____ days
Complement Fixation: Yes or No?
Placental Transfer: Yes or No?
Known Functions: Enhances ______, neutralizes _________, protects ______________
Monomer
80
23
Yes
Yes
phagocytosis
toxins and viruses
fetus and newborn.
Immunoglobulin Classes
II. IgM
Structure: _______
Percentage serum antibodies:____%
Location: Blood, lymph, B cell surface (monomer)
Half-life in serum:___days
Complement Fixation: Yes or No?
Placental Transfer: Yes or No?
Known Functions: _________ produced during an infection. Effective against microbes and _______________
Pentamer
5-10
5
Yes
No
First antibodies
agglutinating antigens.
Immunoglobulin Classes
III. IgA
Structure: ______
Percentage serum antibodies: ____%
Location:_______ , blood and lymph.
Half-life in serum: ____ days
Complement Fixation: Yes or No?
Placental Transfer: Yes or No?
Known Functions: Localized _______ of ______. Provides immunity to ________
Dimer
10-15
Secretions
6
No
No
protection of mucosal surfaces
infant digestive tract.
Immunoglobulin Classes
IgE
Structure: _______
Percentage serum antibodies: 0.002%
Location: Bound to _____ and ______ throughout body. Blood.
Half-life in serum:___ days
Complement Fixation: Yes or No ?
Placental Transfer: Yes or No?
Known Functions: ______ reactions. Possibly ________
Monomer
mast cells and basophils
2
No
No
Allergic; lysis of worms.
Immunoglobulin Classes
IgD
Structure: ________
Percentage serum antibodies: ____% Location: B-cell surface, blood, and lymph
Half-life in serum:___ days
Complement Fixation: Yes or No?
Placental Transfer: Yea or No?
Known Functions: In serum function is unknown. On B cell surface, initiate immune response.
Monomer
0.2
3
No
No
Arrange the IGs in order of :
Decreasing half life
Decreasing serum percentage
G A M D E
G A M D E
IGs structure
G
A
M
E
D
Monomer
Dimer
Pentamer
Monomer
Monomer
Which IGs can cross placenta?
Only G
Which IGs can fix complement?
G
M
Most IGs decrease in ???
Congenital Aggammaglobulinemia
Hypogammaglobinemia
Ig deficiency states
CLL
Lymphoid aplasia
In IgG and IgA myeloma , there will be ____ deficiency
IgM
In IgA myeloma , there will be ____ deficiency
G
In IgG myeloma , there will be ____ deficiency
IgA
Most IGs increase in ???
chronic infections
Their immunoglobulin Myeloma
Autoimmune disorders
Liver disease
In hyperimmnunization, there is increase in Ig____
G
In Waldenstrom’s macroglobulinemia, there is increase in Ig____
M
In malaria, there is increase in Ig____
M
In Trypanosomosis, there is increase in Ig____
M
In atopic skin diseases, there is increase in Ig____
E
In anaphylactic shock, there is increase in Ig____
E
In asthma , there is increase in Ig____
E
In hay fever, there is increase in Ig____
E
In eczema, there is increase in Ig____
E
