How do specific and nonspecific binding factor into calculations for a competitive binding assay to find the affinity of an agonist? For example, are they calculated before or after the assay, and does it affect the binding isotherm curve and how it is calculated?

How does a competitive binding assay determine the affinity for an agonist? Specifically, how is the competition measured and the number of receptors/ligands counted?

How can the dissociation equilibrium constant, and the total number of receptors be calculated from a binding curve in a radiolabeled ligand saturation assay?

You are studying the uptake of L-leucine by epithelial cells of the mouse intestine. Measurements of the rates of uptake of L-leucine and severalof its analogs, with and without Na+ in the assay buffer, yield the results given in the table below. What can you conclude about the properties and mechanism of the leucine transporter? Would you expect L-leucine uptake to be inhibited by ouabain?

You are a technician in a biochemistry lab running receptor binding experiments. The target membrane-bound receptor has been partially purified from mouse, rat, and human cell lines. Using the same radioactive ligand in a saturation binding assay for each species' receptor, you generate the binding data in the table. The dependent variable, Y, is the fraction of binding sites occupied by the ligand. Ligand Y for mouse Y for rat Y for human concentration receptor receptor receptor (nM) 0.20 0.048 0.29 0.17 0.50 0.11 0.50 0.33 1.0 0.20 0.67 0.50 4.0 0.50 0.89 0.80 10 0.71 0.95 0.91 20 0.83 0.97 0.95 50 0.93 0.99 0.98 Determine the Ka for the human receptor in this binding experiment. human receptor Kd nM

Which ONE of these statements is the most accurate definition of the mode of action of imatinib? Select one: A.It is a specific inhibitor of the BCR‐ABL1 fusion protein and blocks phosphatase activity by competing with adenosine triphosphate (ATP) binding B.It is a specific inhibitor of the BCR‐ABL1 fusion protein and blocks tyrosine kinase activity by competing with adenosine triphosphate (ATP) binding C.It is a specific inhibitor of the BCR‐ABL1 fusion protein and blocks tyrosine kinase activity by interaction with the enzyme site D.It is a specific inhibitor of the BCR‐ABL1 fusion protein and blocks phosphatase activity by interaction with the enzyme site

The distal Histidine (His 64) in myoglobin is subjected to three different mutations, this is one of them: H64N. (Histidine to Aparagine)   For the mutation, draw a theoretical binding curve and CO relative to the O2 and CO binding curves for wild-type Mb (see example below). Provide a clear rationale for the binding curve.

In the "biochemical assay of b-galactosidase activity", what is o-nitrophenyl-b-D-galactosidase (ONPG) used for? O When ONPG is cleaved by b-galactosidase, we are able to assay b-galactosidase activity. O It provides essential nutrients for bacterial growth. It partially disrupts the cell membrane to allow cellular proteins to diffuse out of the cell. O ONPG cleaves the b-galactosidase that is made by the lac operon so we can see how much activity there is in the cell. ONPG cleaves galactose so we can measure how much lactose there is in the cell.

How do we calculate Ki of an inhibitor?  Also, is Kapp the same as Km or does Kapp involve more variables?

During an SAR effort to identify tyrosine kinase inhibitors, it was found that compound 2 was significantly more potent and selective than compound 1. To what might you attribute this improvement in activity and selectivity? Explain. IC-5 micromolar IC-0.1 mromolar