1. Hemoglobin Hb Arwa Almejbel

2. Introduction First studied in the 1800 th. Third of red blood cells is hemoglobin. Found in bacteria,eukaryotic organisms and archea. The heme part is synthesized in mitochondria and cytosol in While the globin protein parts are synthesized by ribosomes in the cytosol. Function: to transport the oxygen and maintain the round shape of the RBCs.

3. Hemoglobin A Structure Heme Red is Heme, gray is α chain and blue is β chain. PDB ID: 1HGA α1α1 β1β1 β2β2 α2α2

4. Amino acid sequence Alignment Glu6 His58 Val62 His87

5. Key amino acids in Hemoglobin PDB ID: 1HGA

6. Oxygen binding Cooperative binding Binding to the 1 st O 2 facilitates the binding of 2 nd,3 rd and 4 th O 2. Binding to O 2 causes conformational changes.. O 2. PHE. H 2 O. HIS. VAL PDB ID: 1GZX

7. Oxygen-Hemoglobin binding Partial pressure of oxygen determines how much oxygen binds. The affinity of O 2 depends on PH. Small amount of CO reduces Hb ability to transport O 2 https://thechronicleflask.wordpress.com/tag/red-blood-cells/

8. The T and R transition T formR form PDB ID: 1HGAPDB ID: 1BBB

9. Salt Bridges in Deoxy Hb http://employees.csbsju.edu/hjakubowski/classes/ch331/bind/olbindhemoglobin.html

10. Mutations in hemoglobin (hemoglobinopathies): Sickle cell anemia (Hb S): http://www.cc.nih.gov/ccc/ccnews/nov99/

11. structure PDB ID: 1GZX

12. Hydrophobic pocket PDB ID: 2HBS Val6, Leu88, Phe85

13. Lifetime of RBC in Sickle cell is 20 days. As the cell sickle it causes a low oxygen conc. region. Lose of elasticity Unable to flow through capillaries.

14. References Harrington, D.J., Adachi, K., Royer Jr., W.E. (1997) The high resolution crystal structure of deoxyhemoglobin S. J.Mol.Biol. 272: 398-407 Shaanan, B. Structure of human oxyhaemoglobin at 2.1 A resolution. (1983) J.Mol.Biol. (171) 31-59 http://employees.csbsju.edu/hjakubowski/classes/ch331/bind/olbindhemoglobin.html Marengo-Rowe,A. J. (2006) Structure-function relations of human hemoglobins. Proc (Bayl Univ Med Cent)19(3) 239–245. Paoli, M., Liddington, R., Tame, J., Wilkinson, A., Dodson, G. (1996) Crystal structure of T state haemoglobin with oxygen bound at all four haems. J.Mol.Biol. 256(4):775-92. PDB ID: 1BBB Liddington, R., Derewenda, Z., Dodson, E., Hubbard,R, and Dodson, G. (1992) High resolution crystal structures and comparisons of T-state deoxyhaemoglobin and two liganded T-state haemoglobins: T(alpha- oxy)haemoglobin and T(met)haemoglobin. J Mol Biol. 228(2)551-79. PDB ID: 1HGA Starr C., Taggart, R. (2001) Biology: The Unity and Diversity of Life (6 th Ed.) pp. 183-227, Brooks/Cole, Pacific Grove. Rousseot, N., Jaenicke, E., Lamkemeyer, T., Harris, J.R., Pirow, R. (2006) Native and subunit molecular mass and quarternary structure of the hemoglobin from the primitive branchiopod crustacean Triops cancriformis. FEBS J 17, 4055-71. Campbell, N.A., Reece, J.B., Taylor, M.R., Simon, E.J. (2006) Biology Concepts and Connections (Eds.) (5 th Ed.) pp. 46-462, Pearson, San Francisco. Alberts, B., Johnson, A., Lewis, J., Raff, M., Roberts, K., Walter, P. (2002) Molecular Biology of the Cell. (Eds.), pp. 461, Garland Science, New York. http://www.cc.nih.gov/ccc/ccnews/nov99/