Log in
HomeClass Notes1,200,000CA670,000

BIOL130 Lecture Notes - Lecture 2: Red Blood Cell, Valine, Hemoglobin

85 views5 pages
cerisegiraffe538
29 Sep 2015
School
University of Waterloo
Department
Biology
Course
BIOL130
Professor
Heidi Engelhardt

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Biol 130 lecture 3 unit 2b macromolecules ctnd. Sickle cell anemia: the hemoglobin in your blood is made of protein. If the primary structure (the arrangement of amino acids) is changed, the entire structure of the protein is affected. It can be either -helices or -pleated sheets. Helices: the 3d shape is like a spring (coiled up) Helix faces": the r groups coat the outer surface of the helix. If they have hydrophobic side chains, they do not want to be in the hydrophilic cytoplasm, but the cell membrane. Insulin that is secreted out into the areas of the body where it is needed. Protein stability: they are stabilised by weak interactions, therefore they are not very stable, minor changes to the environment cause denaturing (unfolding, destruction of the tertiary and /or secondary structure, note: the primary structure is not affected.

Get access

Grade+
$40 USD/m
Billed monthly
Grade+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
10 Verified Answers
Class+
$30 USD/m
Billed monthly
Class+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
7 Verified Answers

Related Documents

BIOL130 Lecture Notes - Lecture 5: Sickle-Cell Disease, Lipid Bilayer, Beta Sheet
amethystsalmon420
BIOL130 Lecture Notes - Lecture 5: Sickle-Cell Disease, Point Mutation, Protein Structure
periwinklehorse340
BIOL130
Final Exam
Study Guide
BIOL130 Study Guide - Midterm Guide: Ethanol Fermentation, Glycosidic Bond, Glycogen
azurehippopotamus433

Related Questions

16. Sickle cell anemia is a genetic disorder resulting in an alternation of the structure and function of hemoglobin. Specifically, the amino acid valine replaces glutamate in a position located in the surface of the protein. Based on your knowledge of protein sequence answer the following:

a. At what level of protein structure does the amino acid substitution occur? Explain?

b. Provide a biochemical rationale for why this change in the sequence of hemoglobin’s beta chain results in red blood cells sickling. Your answer should include reference to structures of valine and glutamine shown above.

Below is the protein sequence for the beta subunit of human hemoglobin (using the one letter abbreviations for amino acids). Use it to answer the following questions.

Write the order of the LAST 10 amino acids in this protein.

For each of the LAST 10 amino acids, tell one other amino acid that it would favorably interact with (i.e. could form a bond with).

In sickle cell anemia, the first glutamate (E) is mutated to valine (V). Propose a hypothesis on how this change of amino acid will affect the folding of the hemoglobin protein and why the hemoglobin function will change.

 MVHLTPEEKSAVTALWGKVNVDEVGGEALGRLLVVYPWTQRFFESFGDLSTPDAVMGNPKVKAHGKKVLGAFSDGLAHLDNLKGTFATLSELHCDKLHVDPENFRLLGNVLVCVLAHHFGKEFTPPVQAAYQKVVAGVANALAHKYH

Normal adult hemoglobin is called Hemoglobin A (Hb A). Ninety-eight percent of adult hemoglobin is Hb A and 2% is Hb A2. There are other forms of hemoglobin. For example, the developing fetus has a different kind of hemoglobin than most normal adults. Fetal hemoglobin (Hb F) is synthesized beginning at the third month of gestation and continues up through birth. After the neonate is born, hemoglobin F synthesis declines (because synthesis of the (chain declines) and hemoglobin A is synthesized. By the time the baby is six months old, 98% of its hemoglobin is Hemoglobin A. There is also a mutant form of hemoglobin called Hemoglobin S, which is found in persons with the disease sickle cell anemia. The disease sickle cell anemia is one of the major health problems facing the African-American community. The World Health Organization estimates that 250,000 babies world wide are born with sickle cell anemia. Currently there is no cure. A person afflicted with sickle cell anemia has inherited a defective gene from each parent. The defective gene is the one coding for the β-chain. The amino acid at position 6 on each β chain has been mutated from a glutamate to a valine. Normal α chains have a decreased affinity for the mutated β chains; thus assembly of the HbS tetramer is more difficult. Red blood cells containing HbS form a sickle shape because the Hb S molecules polymerize. Hb S molecules are more likely to polymerize when in the deoxygenated T form than in the oxygenated R form. The polymerized Hb deforms the normal discoid shape of the red blood cells, producing a sickle-shaped cell. The sickle shaped red blood cells become trapped in capillaries and organs, depriving the victim of adequate oxygen supply and causing chronic pain and organ damage.

Glover, R. E., Ivy, E. D., Orringer, E. P., Maeda, H., and Mason, R. (1999) Molecular Pharmacology 55, pp. 1006-1010.

Huang, J., Hadimani, S. B., Rupon, J. W., Ballas, S. K., Kim-Shapiro, D. B., and S. Bruce King (2002) Biochemistry 41, pp. 2466-2474.

S. Bruce King (2003) J.Clin. Invest., 111, pp. 171-172.

1) Why do you think Hb S has higher tendency to polymerize compared to Hb A?