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?

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

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

One of your colleagues has obtained a sample of muscle phosphorylase b that is known to be relatively inactive. She has approached you for advice on how to set up an appropriate assay. She has the following items available, not all of which are appropriate for this study. Help her out by selecting the items that she should use and what their purpose is in the assay, and then explain why each of the other items would not be useful. 1. 100 UM AMP 2. 100 UM GTP 3.100 uM glucose 4. 100 uM glucose 6-phosphate 5. Branched glycogen 6. Amylose (i.e. unbranched glycogen) 7.50 mM HEPES buffer, pH 7.5 8. 50 mM potassium phosphate buffer, pH 7.5 Write out a short explanation for each of the above items, and upload your answers by the due date.

Measure the uptake of leucine by epithetial cells of the mouse intestine. Measurements of the rate of update of L-leucine, D-Leucine, and L-valine , with and without Na+ in the assay were perform and yield different results (see table below). A) What can you conclude about the properties and mechanism of leucine transporter? B) Would you expect L-leucine uptake to be inhibited by Ouabain, which is a cardiac glycoside drug treatment?

Inhibitors of acetylcholinesterase, such as edrophonium, are used to treat Alzheimer’s disease. The substrate for acetylcholinesterase is acetylcholine. Structures are attached.   What kind of inhibitor is edrophonium? Explain. Can inhibition by edrophonium be overcome in vitro by increasing the substrate concentration? Explain. Does this inhibitor bind reversibly or irreversibly to the enzyme? Explain.

Can you explain the experimental procedure from this article? Please explain as if your having discussions with the whole class step by step.

Data from enzyme inhibition are used to determine a Kmapp and Vmax PP. Comparison of these values with assays run without inhibitor are used to understand how the inhibition is occurring. This is useful for better understanding the active site as well as the practical aspect of pharmaceutical drugs. Below are idealized Line-Weaver Burke plots of different types of inhibitors. Comnetitive Uncomnetitive Mixed +Inh +Inh 4Inh Anh Inh Anh [S] [S] [S] a. How does the value of Vmax for the enzyme compare to the Vmax PP of the inhibited enzyme for: i. Competitive ii. Uncompetitive iii. Mixed b. How does the value of Km for the enzyme compare to the Km PP of the inhibited enzyme for: i. Competitive ii. Uncompetitive iii. Mixed c. For each situation in Model 1, consider an inhibitor that is better than the one shown on the graph. Answer the following questions for each type of inhibition: i. How would the KmPP change? ii. How would the Vmax PP change?