Week 8 - Proteins, Immunoassays, and Binding Affinity

These flashcards cover key concepts from the lecture on proteins, immunoassays, and binding affinity, including ionization, protein charges, antibody structure, and purification techniques.

ionizable groups in amino acids include __.

Carboxylic acid, amine, thiol, phenol.

At pH = 7, the amino group is __.

Cationic.

Cys thiol has a pKa of __.

8.6.

The isoelectric point (pI) of a protein is the pH at which the protein has __ charge.

Net zero.

Histones exemplify proteins with __ charge due to excess cationic groups.

Net positive.

Immunoassays utilize the specificity of __ to detect antigens.

Antibodies.

The variable region of an antibody is responsible for __ binding.

Antigen.

In SDS-PAGE, proteins are denatured and coated with __ to ensure migration regardless of charge.

Anionic detergent.

The pKa value of histidine imidazole is approximately __.

6.5.

SARS-CoV-1 spike binds tightly to m396 Fab with a Kd of __.

20 nM.

The fraction occupancy (θ) of a binding site can be calculated by __.

[Bound] / ([Bound] + [Free]).

Lower values of Kd represent __ binding affinity.

Tighter.

An ionic exchange chromatography separates proteins based on __.

Charge.

In protein purification, chromatography exploits differences in __ among proteins.

Physical properties.

Antibodies can block the function of an antigen by __.

Occupying its binding site.

Immunoblots help determine the __ of a target protein on a membrane sheet.

Location.

The constant part of the antibody is known as the __ region.

Fc.

The CDRs (complementarity-determining regions) are located in the __ part of an antibody.

Variable.

As pH increases, the net charge of aspartic acid decreases from __ to a number closer to zero.

+1.

The pKa of the carboxylic acid in aspartic acid is approximately __.

3.9.

Isoelectric point (pI) is the pH where the net charge is __.

Zero.

Sodium Dodecyl Sulfate is used in __ to denature and separate proteins.

SDS-PAGE.

The binding affinity of an antibody for its target is quantified using the __ constant.

Dissociation (Kd).

Antibodies that arise from a single clone of B lymphocytes are termed __ antibodies.

Monoclonal.

In co-immunoprecipitation, the target protein binds __ proteins in a complex.

Other.

In antibody technology, the binding specificity refers to the ability to effectively __ one partner over another.

Bind.