1. Amyotropic lateral sclerosis (ALS) is correlated with a low activity of superoxide dismutase (SOD).
How would you test the hypothesis that degeneration of motor neurons in ALS is linked to low activity of SOD and production of reactive oxygen species (ROS)?
You have available mutant mice lacking functional SOD, a variety of antioxidants, inhibitors of SOD and biochemical techniques for measuring ROS damage.
2. Nobel prizes are rarely given to individuals. Describe the research project undertaken by your group that will win a Nobel Prize in 2030. Your description of the project must include (a) a description of the problem and (b) the biochemical basis of what you are going to study.
3. Several speakers talked of mutations. How might mutations effect a protein's structure and function?
1.
ALS genes encode mutant SOD: SOD activity decreases, ROS increases --> ALS.
Molecular biology:
Cross mutant mice, SOD-/+, knock-out mice, SOD-/-, and normal mice, SOD+/+, and correlate SOD activity, [ROS] and ALS: all crosses exhibit pathology, but SOD m/+ or -/+ should have intermediate levels or less pathology. As controls use ALS in -/-, +/+. Even better if you can get an overproducer with elevated SOD activity.
Drugs:
Use antioxidants, high doses to reduce [ROS] and incidence of ALS or alleviate symptoms.
Measure decrease in patients.
Delay onset in mouse model.
Measure products of ROS damage -- membranes.
Inhibitors:
Inhibitors of SOD enzyme activity should increase ALS in +/+ mouse model.
2.
Clear explanation of the problem.
Clear explanation of the biochemical problem.
Develop an hypothesis.
Experimental basis and outcomes. Controls are important.
3.
No protein produced, deletions or addition. No protein activity.
No functional protein produced, point mutations, frame-shift mutations, single amino acid replacement altering activity. No protein activity.
Lower protein activity, point mutations, frame-shift mutations, single amino acid replacement altering activity.
Altered tertiary structure (folding) thereby altering activity, or altering targeting signals so that the protein doesn't get to the right location (cystic fibrosis)