HomeCoursesMEDSCI 204: Pharmacology and ToxicologyLecture 4 Lecture 4 1. What are the purposes to measuring receptor binding? "To determine mechanism of action, validate new drug moa, prerequisite of drug development"What are the purposes to measuring receptor binding?== "To determine mechanism of action, validate new drug moa, prerequisite of drug development" 2. What does measuring receptor binding NOT tell us? "Efficacy, other targets, although potential efficacy can be inferred"What does measuring receptor binding NOT tell us?== "Efficacy, other targets, although potential efficacy can be inferred" 3. How are ligands detected? Radioactively labelled compoundHow are ligands detected?== Radioactively labelled compound 4. What target samples are used? "Whole cells, homogenised cells, tissue"What target samples are used? =="Whole cells, homogenised cells, tissue" 5. What is binding equilibrium? [Kd] is 50% functional occupancyWhat is binding equilibrium?== [Kd] is 50% functional occupancy 6. What is Bmax? SaturationWhat is Bmax?== Saturation 7. What does washing do? Removes unbound ligandWhat does washing do?== Removes unbound ligand 8. What are the properties of washing? "cold, rapid"What are the properties of washing?== "cold, rapid" 9. How are binding signals measured?== "Scintillation, tritium sensitive film" 10. What is non specific binding? Binding of compounds to cells/tissue other than receptorWhat is non specific binding?== Binding of compounds to cells/tissue other than receptor 11. What is a feature of non specific binding? Non saturableWhat is a feature of non specific binding?== Non saturable 12. What is total binding? Receptor binding + non specific bindingWhat is total binding?== Receptor binding + non specific binding 13. How to determine non specific binding? Assay with non-labelled compound and labelled compound with high concentration of nonlabelled to saturation. Non specific binding can then be measured through radiolabelled binding to nonspecific sitesHow to determine non specific binding?== Assay with non-labelled compound and labelled compound with high concentration of nonlabelled to saturation. Non specific binding can then be measured through radiolabelled binding to nonspecific sites 14. What is competition binding? Measuring labelled ligand to get binding information on unlabelled ligandWhat is competition binding? ==Measuring labelled ligand to get binding information on unlabelled ligand 15. What is B0 on a competition binding curve? Radioligand binding and Kd without competitorWhat is B0 on a competition binding curve?== Radioligand binding and Kd without competitor 16. What is IC50? Concentration at which unlabelled ligand displaces 50% of specific radioligand bindingWhat is IC50?== Concentration at which unlabelled ligand displaces 50% of specific radioligand binding 17. What is the equation for affinity for unlabelled ligand? Ki equals IC50/2What is the equation for affinity for unlabelled ligand?== Ki equals IC50/2 18. How to measure specific binding? Total binding - non specific bindingHow to measure specific binding? ==Total binding - non specific binding 19. What is Bmax? Maximum binding (saturation)What is Bmax? ==Maximum binding (saturation) Loading...
