Oxymyoglobin

Oxymyoglobin is shown with layers of <font color=red>water</font> bound to its surface. This water is strongly attracted to the protein and is part of the crystal structure. Removing the <scene name='Oxymyoglobin/Water_removed/1'>water</scene> reveals that the overall tertiary shape is much like a hockey puck. The <scene name='Oxymyoglobin/Secondary_structure/1'>α-helix</scene> is a prominent secondary structural component. Since the secondary structures of myoglobin and oxymyoglobin are essentially identical, go to [[Myoglobin]] for more detail on the secondary structure. The а-helices can be shown to form <scene name='Oxymyoglobin/Two_layers/2'>two layers of backbone</scene>, and myoglobin can be classified as an antiparallel α-helix type of globular protein. The <scene name='Oxymyoglobin/Rama/1'>Ramachandran plot</scene> shows most of the residues involved in an α-helix are clustered in the area of the plot where one would expect them to be. (Review [[Ramachandran Plot]].) Many of the residues that are outside of the expected cluster are at the end of a helix, and it is not unusual for such residues to have ψ and φ values that are outside of the normal range. Also notice that many of the residues that are in the quadrants on the right are Gly. (Residues can be identified by hovering over the sphere with the cursor.) The prosthetic group of myoglobin is a <scene name='Oxymyoglobin/Heme/2'>heme</scene>, and as shown here it is inserted into a nonpolar pocket in the protein.