BIOLOGY 190A Lecture Notes - Lecture 15: Beta Sheet, Valine, Hemoglobin
13 Jan 2016
School
Department
Course
Professor
Document Summary
Sickle cell anemia case study: dr. castle did not initially tell dr. pauling which samples came from sickle-cell individuals because this could compromise the integrity of the experiment. This affects a beta sheet that would normally be exposed to water by making it insoluble, therefore promoting the formation of a larger insoluble region in the deoxygenated form of hemoglobin. It is thought that this lower solubility is what results in the long fibers characteristic of sickle cell anemia1: linus pauling"s results are supported by vernon ingram"s results. Vernon ingram"s results indicate that hemoglobin purified from individuals with sickle cell anemia would be less negatively charged than hemoglobin purified from individuals without sickle cell anemia. This is because of the chemical properties of glutamic acid and valine. Glutamic acid has a negative charge, and valine has no charge2. Because sickle cell hemoglobin has an extra valine in replace of a glutamic acid, the hemoglobin is less negatively charged.
