Immunology & Serology - Lecture - 4 - Antibodies/Immunoglobulins - Ig table lacking

Immune system

It functions to protect the body and fight off infection

Yes

Yes or No

Barriers like the skin & mucous membranes and exoskeletons block the entry of illness-causing microorganisms (pathogens like bacteria and viruses). Secretions from these barriers also strengthen that protection

Lymph

Antibodies are specialized proteins circulating through the blood or through a fluid called the _____

Antigens

Antibodies circulate through the blood and carry with them binding sites that attach to harmful invaders collectively known as ________.

Yes

Yes or No

Are viruses, bacteria, fungi, cancer cells, and other allergens considered antigens?

B cell surface

Where are antibodies located?

Antibodies

They act as receptors that precisely identify foreign antigens in order to start an immune response.

Differentiation

Antigen-induced B lymphocyte stimulation will result in _____

Plasma cell

B cell differentiation will result in what cell?

Antibodies

What substance do plasma cells release into the blood and other body fluids?

Antibodies

Released by B cells, they carry out biological functions that render hazardous microorganisms inactive and aid in the removal of these foreign substances from the body.

Immunoglobulin

Other name for antibody

Antibodies

These are specialized globular glycoproteins that play a vital role in immunity

86-98%

What percent of antibodies are composed of polypeptide?

2-14%

What percent of antibodies are composed of carbohydrates?

Antibodies

They are the main humoral element of the adaptive immune response

Antigen recognition, Opsonization, Complement activation

What are the different functions of antibodies?

Antigen recognition

What function of antibodies means there is direct binding between the intact antigen and antibody?

Opsonization

What function of antibodies means to hasten or enhance phagocytosis?

20%

Antibodies constitute what percent of plasma proteins?

Serum protein electrophoresis

What procedure detects the amount of antibodies in the plasma?

Agarose gel

What medium is the serum sample put on when performing electrophoresis?

Electrophoresis

This procedure has an electrical current is applied to separate out the proteins

pH 8.6

At what pH can most serums be separated based on their charges and size.

Albumin, alpha1, alpha2, Beta, Gamma

5 distinct bands or regions in serum electrophoresis

Immunoglobulins

They are the slowest moving proteins in serum electrophoresis

Close to neutral

What is the charge of immunoglobulins?

Gamma region

Where do immunoglobulins primarily appear in serum electrophoresis?

Gamma globulins

Other name for immunoglobulins

Four-chain tetrapeptide unit

It is the basic structure of all immunoglobulin molecules

2 heavy chains, 2 light chains

What are the different chains of the four-chain tetrapeptide unit of all immunoglobulins?

Disulfide bonds

A pair of identical heavy or light chains are held together by _____

1

How many variable regions does each immunoglobulin have in every chain?

1 or more

How many constant regions does each immunoglobulin have in every chain?

VH, CH1, CH2, CH3

Heavy-chain sequencing

50,000-70,000 daltons

Molecular weight of the immunoglobulin heavy chains that extend the full length

Constant region

What region of the heavy chains are unique to each class and gives each immunoglobulin type its name?

Gamma

What Greek letter is used for IgG?

Mu

What Greek letter is used for IgM?

Alpha

What Greek letter is used for IgA?

Epsilon

What Greek letter is used for IgE?

Delta

What Greek letter is used for IgD?

22,000 daltons

Molecular weight of antibody light chains

Light chain

These chains are found on all types of immunoglobulin molecules but do not extend the full length.

1

How many variable regions does a light chain have?

1

How many constant regions does a light chain have?

Kappa chain, Lambda chain

Two main subtypes of light chains that do not have any functional difference

60%

Kappa chains make up what percentage of light chains?

40%

Lambda chains make up what percentage of light chains?

Kappa chain

What subtype of light chains are more predominantly seen?

Yes

Yes or No

Only 1 type of light chain is present in a given molecule

2:1

Kappa to Lambda chain subtype ratio in light chains

200-220 amino acids

How many amino acids are in each light chain?

111

From what position number of the light chains do amino acids start?

Variable region

This region is located in the amino terminal end of the antibody molecule

Variable region

This region defines the specificity of an antibody

Variable region

This region is the first 110 amino acids of an antibody

Constant region

This region is found on the carboxy terminal end of the antibody

111

What amino acid does the Constant region start onwards for both H and L chains?

1 or more

Heavy chains have how many constant regions because it extends the full length of the molecule?

3 or more

The Constant region of an antibody can be divided into how many constant regions with very similar sequences, designated as CH1, CH2, CH3.

IgM

What antibody has an extra 4th domain (CH4)?

1950-1960s

When was the structure of the antibody first described?

Gerald Edelman, Rodney Porter

They first described the structure of the antibody

IgG

What antibody did Gerald Edelman and Rodney Porter use for their research because it was the most prevalent in the body?

IgG

It is the most prevalent antibody in the body

Gerald Edelman

He separated out immunoglobulins on the basis of molecular weight using the analytic ultracentrifuge.

Gerald Edelman

He found out that an intact IgG molecule had a sedimentation coefficient of 7s

7S

Sedimentation coefficient of IgG

Sedimentation coefficienct

It is used to characterize a behavior of a molecule in sedimentation process, notably, centrifugation

Svedbergs unit

How is sedimentation coefficient expressed?

Svedbergs unit

This indicates the sedimentation rate in an analytical ultracentrifuge

S

What letter symbolizes Svedbergs unit?

7 moles of urea

What did Gerald Edelman use to unfold the IgG molecule?

Mercaptoethanol

What reducing agent did Gerald Edelman use to cleave the exposed sulfhydryl bonds?

Centrifugation

After Gerald Edelman cleaved the sulfhydryl bonds of the unfolded IgG, what procedure did he do next?

3.5S

What is the sedimentation coefficient of the heavy chain of IgG?

2.2S

What is the sedimentation coefficient of the light chain of IgG?

H2L2

This formula became the generalized formula for all immunoglobulin molecules

Rodney Porter

He used the proteolytic enzyme papain to cleave IgG into 3 pieces of equal size (3.5S)

Papain

What proteolytic enzyme did Rodney Porter use to cleave the IgG molecule into 3 equal pieces?

3.5S

What is the sedimentation coefficient of each piece of the 3 equal pieces of IgG Rodney Porter cleaved?

Ion exchange chromatography

How did Rodney Porter split a single antibody molecule into 3 fragments?

1 Fc fragment, 2 Fab fragments

What were the 3 fragments the IgG was split into?

Papain cleavage

Papain cleaves the IgG or the antibody molecule below the set of disulfide bonds that holds the 2 heavy chains together that resulted in the formation of 3 fragments.

Fc region

What antibody region is the only intact region after papain digestion?

Fragment antigen-binding

What antibody region is separated out after papain digestion?

No

Can an antibody, after papain digestion, agglutinate? Even if the binding sites are separated out and is not enough to cause agglutination?

Alfred Nisonoff

He used pepsin to cleave IgG at the carboxyterminal side of the interchain disulfide bonds, yielding one single fragment with a molecular weight of 100,000 d and all the antigen-binding ability, known as F(ab')2 fragment.

Pepsin

What enzyme did Alfred Nisonoff use to cleave IgG at the carboxyterminal side?

Fc', F(ab')2

What were the 2 fragments that Alfred Nisonoff yielded by cleaving IgG using pepsin?

Fragment crystallizable

What region was disintegrated when IgG was cleaved into 2 fragments using pepsin?

Fragment antigen-binding

These 2 fragments were still intact to each other when Alfred Nisonoff used pepsin to cleave IgG.

Disulfide bonds

These are the bonds that held together the 2 Fab fragments when Alfred Nisonoff cleaved IgG with pepsin

Fragment crystallizable

Fc meaning

4°C

At what temperature does Fc fragment spontaneously crystallize?

Fc fragment

This antibody fragment represents the carboxy-terminal halves of two heavy chains which are all constant regions.

Fc fragment

This antibody fragment has no antigen binding capacity

Fc fragment

This antibody fragment is responsible for the biological activity of the molecule (effector functions).

Fc fragment

This antibody fragment has effector functions