Sandbox GGC8

Hemoglobin A

spinqualitylabelsall models Caption for this structure Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D DEOXY HUMAN HEMOGLOBIN A Function Hemoglobin A is an oxygen-transport protein. Hemoglobin is also an allosteric protein. It is a tetrameter composed of two types of sub units designated α and β, with stoichiometry α2β2 The function of Hemoglobin is to carry oxygen from the lungs to the other parts of the body . Hemoglobin also help to carry carbon dioxide through the blood cells.Hemoglobin A which is a component of the red blood cells also help with the transportation of carbon dioxide and hydrogen ions to the lungs. Hemoglobin proteins are capable of carrying four molecules of Oxygen . Hemoglobin also help red blood cells to maintain their disc like shape , which allows them to move freely through the blood vessels. Each sub-unit of Hemoglobin A contains a heme prosthetic group. The heme molecules give hemoglobin its red color. Disease The most well-known disease caused by mutation in the hemoglobin A protein is sickle-cell anemia. Sickle-cell anemia results from a mutation of the sixth residue in the β hemoglobin monomer from glutamic acid to a valine. This hemoglobin variant is termed 'hemoglobin S' (2hbs). Relevance Most of the understanding that of human physiology and pathology come from laboratory research that were performed on Hemoglobin . Hemoglobin A is important for the body ;it helps the body to maintained a balanced amount of red blood cells.Low red blood cells in the body tissues can cause fatigue and weakness. Structural highlights Proximal His87 and the distal His 58The α chain heme pocket with the relative orientation of the proximal Hisα87 and the distal Hisα58.proximal Hisα87(F8) is closer to the heme Fe atom by 0.10 Å more in the T-state compare to the R-state. Proximal 92 His and distal 63 His The β chain heme pocket with the proximal Hisβ92(F8) and the distal Hisβ63(E7). In the R-state the proximal Hisβ92(F8) reorients itself to a more symmetric position relative to the heme molecule. In the T-state, the distal histidine E7 residue is positioned such that it partially blocks the oxygen-binding site. During the R → T transition, Hisβ63(E7) aligns itself with the heme Fe, and the Fe-His distances increase by a small but detectable amount

References

Crystal structure of Lysβ182-Lysβ282 crosslinked hemoglobin: A possible allosteric intermediate1 https://www.sciencedirect.com/science/article/pii/S0022283600935253?via%3Dihub#FIG4

https://www.verywellhealth.com/importance-of-hemoglobin-2249107