Pharma Research

 

Ragnarsson L, et al. Extracellular surface residues of the alpha1B-adrenoceptor critical for G protein-coupled receptor function. Molecular Pharmacology 87: 121-129, 2015.

 

REMINDER:  If you are using any direct quotes from the paper (or other sources) in your answer, please remember to use quotation marks and/or sources.

 

 

1. (2) Read the abstract for the paper.

What is the hypothesis they propose to test?

 

 

 

2. (4) Using the abstract AND the rest of the paper:
3. How do they propose to test this hypothesis?

 

 

 

1. What region of the receptor do they plan to examine?

 

 

 

1. Once they create the mutations in the receptor, how do they plan to assess the function of the mutant receptors (HINT: what properties of receptor function do they plan to assess?)

 

 

 

3. (2) The researchers employed a technique referred to as “alanine scanning mutagenesis”. MANY scientific papers would have included literature citations in the References section that would explain the method and the rationale for its use. This paper, however, does not.

 

List two approaches that you could use for an internet search strategy to find out about the technique of “alanine scanning mutagenesis”. Include your rationale for each approach

1. Approach: One approach I could take is to type in exactly what I am looking for in Google Scholar, and clink on a link and filter the results.

 

 

Rationale:

 

 

1. Approach: Another approach is going to a database website, and performing an advanced search.

 

 

Rationale: If I went on the to American Society of Microbiology, it would allow me to perform an advance search, that would allow the for the filtering of key phrases,

 

 

4. (4) Using one of your search strategies, identify another scientific paper published within the past two years that has also utilized this strategy:

 

1. List the citation here:

 

 

1. Using the resources you have through the online Scott Library, you want to find the fastest way to obtain the article (so that you could read it). Describe how and where you would obtain the article.

 

 

5. (4) Give a brief description of “alanine scanning mutagenesis”. Why is the rationale for using the amino acid alanine (it may be helpful to show amino acid structures).

 

 

 

 

 

3. (4) Back to the paper: Table 1 summarizes the data from 5 different sets of experiments.
4. Which set(s) of data showed the MOST residues with statistically significant differences from the WT receptor? ______________

 

 

1. Which set(s) of data showed the FEWEST residues with statistically significant differences from the WT receptor? ________________

 

 

1. Which residue is the most “interesting” based on the data presented in this table? ______

 

 

1. Now look at Figure 8 to determine the location of this residue in the sequence (TMH2, ECL1, etc). Where is this residue located? ________________

 

The take home message from looking at the question from multiple perspectives and from multiple sets of experimental data is that you cannot just look at one property in order to get the big picture! If the authors had ONLY looked at the EC50 values for a receptor agonist (here they used Norepinephrine), they would have reached very different and perhaps erroneous conclusions! (Remember that EC 50 is a measure of potency).