Lecture 1 short recap Flashcards
What is affinity?
Affinity is the individual interaction between a ligand and single binding site of a receptor
What is avidity?
The combined affinities of a complex
IgM affinity and avidity?
Has low affinity for antigens but has high avidity as it is pentameric
What are GAGs?
Glycosaminoglycans
What are GAGs composed of?
They are long unbranched polysaccharides made up of multiple disaccharide units
What are the disaccharides composed of?
Amino acid
Uronic acid
What are the 4 types of GAG?
Heparan sulfate
Keratan sulfate
Chondroitin sulfate
Hyaluronic acid
The PfEMP1 variant involved in placental malaria binds to which GAG?
CSA
Chondroitin sulfate A
What are proteoglycans composed of?
GAGs- glycosaminoglycans linked to core proteins
How do TCRs have low affinity but high avidity?
Have high avidity due to T cell capping which involves movement of all the TLRs to a single part of the cell.
Why does IgM bind more tightly than IgG even though IgM has a lower affinity for antigens?
Due to the high avidity of IgM. IgM is pentameric and has 10 binding sites, whilst IgG only has two binding sites
What is the association constant?
Ka
What is the equation of the association constant?
[RL]/[R][L]
What is the dissociation constant?
Kd
What is Kon?
The association rate, the rate at which receptors and ligands associate to form a complex
