Assignment 2

A number of mutations in the hemoglobin protein result in a mutant protein that demonstrates a faster electrophoretic migration pattern on a gel than the normal protein. Pretend you are a biochemist who is interested in identifying hemoglobin mutations of this kind. You have available to you 17 patients who have donated blood samples to your lab, and your laboratory technician has run gels on the hemoglobin samples from these patients. It is now your job to interpret these gels to identify which patients may contain the mutant forms of hemoglobin that you are interested in learning more about.

Select the Gel Electrophoresis view, and examine the electrophoresis pattern for the hemoglobin molecules from each of the patients by clicking on each patient's name.


1 .		Which one of the patients has hemoglobin molecules that show a faster electrophoretic migration pattern than the control molecules?

2 .		Select the Peptide Sequence view and click the Find Difference button to identify the altered amino acid sequence for this patient. What is the mutation that appears? Is this mutation at the N-terminus or C-terminus of the globin polypeptide?

3 .		Provide a possible explanation for why this change in amino acid sequence would cause the mutant protein to show a faster electrophoretic migration pattern than the normal protein.

4 .		Read this patient's case history. This patient's mother has symptoms indicative of a hemoglobin mutation, but the patient's father appears normal. Is the gel electrophoresis pattern that you observed for this patient's hemoglobin consistent with his or her family history? Explain your answer.

5 .		After you meet with this patient and discuss your interest in his or her blood, the patient tells you that his or her mother was born and raised in Hiroshima, Japan. Because you are a well-rounded person with a strong knowledge of world history, what might you consider to be the cause of this patient's hemoglobin mutation?