Hemoglobin and myoglobin

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1. hemoglobin And Myoglobin Presented By: Abdul Basit (42512) Usama Aamir (41585) Presented To: Dr. Asma Abro

2. 2 Contents Introduction Structure Of hemoglobin And Myoglobin Functions Of hemoglobin And Myoglobin Comparison Between hemoglobin And Myoglobin Cooperativity and Allosteric Regulation in hemoglobin Conclusions References

3. 3 Introduction Because of its red colour, the red blood pigment has been of interest since antiquity. First protein to be crystallized - 1849. First protein to have its mass accurately measured. First protein to be studied by ultracentrifugation. First protein to associated with a physiological condition. First protein to show that a point mutation can cause problems. First proteins to have X-ray structures determined. Theories of cooperativity and control explain hemoglobin function

4. 4 Pathway Lungs hemoglobin Myoglobin O 2 O 2 Tissue

5. 5 hemoglobin heme (Blood )-Globin(Protein) heme is a prosthetic group Only Fe ++ Binds Oxygen α 2 β 2 Heterotetramer Transport Protein Myoglobin Myo(Muscle)-Globin(Protein) Storage Protein Monomer (Single Polypeptide Chain)

6. 6 Structure of hemoglobin And Myoglobin heme N α Chain Chain β N N β Chain N α Chain

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9. 9 Functions of hemoglobin And Myoglobin During this process, the hemoglobin macromolecule undergoes conformational changes due to the binding and unbinding of oxygen and carbon dioxide. And it include : Oxygen Pickup Oxygen Delivery Carbon Dioxide Pickup Carbon Dioxide Delivery

10. 10 Further proceed By : Usama Aamir (41585)

11. Comparison Myoglobin Myoglobin is a globular protein . Water soluble. Ligand is oxygen. Myoglobin exist in muscle(tissue). Myoglobin is a storage protein. hemoglobin hemoglobin is also a globular protein. Water soluble. Ligand is oxygen. hemoglobin exist in blood . Hemoglobin is a transport protein. 11

12. 12 Myoglobin hemoglobin Bind And Release O 2 to muscle cell. Monomer (Single polypeptide Chain) 8 Helices segments Tertiary Structure Histidine is present helps to attach with Fe (Iron) Take O 2 From lungs to the tissues (Including Muscles) Oligomeric nature ( More than one polypeptide chain) Actually made up of 2 α and 2 β side chains Quartnery structure Also Attaches with histidine residues to impart some kind of buffering properties to blood

13. 13 Myoglobin hemoglobin Higher affinity towards oxygen because myoglobin needs to grab the oxygen from hemoglobin. Can bind to one heme group (prosthetic group ). Comparatively lower affinity towards oxygen hemoglobin have two states R state ( O xyhemoglobin) And T state ( Deoxyhemoglobin) Can Bind to 4O 2 Molecules each subunit has a heme group.

14. 14 Cooperativity A simple phenomenon in which when one oxygen is bind to one subunit the affinity for O 2 at the other subunit increases. Allosteric regulation Simply, binding of one ligand to a subunit will affect on the affinity of other subunits.

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16. 16 Conclusion Animals Have Widely Varying O 2 Need hemoglobin and Myoglobin are Related , but Have Different Functions hemoglobin has Four Subunits and heme group. Myoglobin has One of Each Bind of O 2 by heme’s Iron Pulls up on a Histidine and Change’s hemoglobin Shape Changing hemoglobin Shape Converts hemoglobin from T-state to R-state R-state Binds Oxygen Better. T-state Releases O 2 Better Sickle Cell Anaemia (SCA) is a Genetic Disease of hemoglobin.

17. References 17 Oxygen binding by myoglobin & hemoglobin. (2004, October 1). Retrieved from https ://www.bio.cmu.edu/courses/03231/LecF04/Lec13/le c13.html Bucci , E., Razynska , A., Kwansa , H., Gryczynski , Z., Colli ns, J. H., & Fronticelli , C. (1996). Positive and negative cooperativities at subsequent steps of oxygenation regulate the allosteric behavior of multistate sebacylhemoglobin . Biochemistry, 35, 3418 - 3425

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