Molecule of the Month: Myoglobin
Myoglobin was the first protein to have its atomic structure determined, revealing how it stores oxygen in muscle cells.
The First Protein Structure
Myoglobin and Muscles
Visualizing Protein Structure
Myoglobin and Whales
Oxygen Bound to Myoglobin
Exploring the Structure
Structural Features of Myoglobin (PDB entry 1mbn)
The atomic structure of myoglobin revealed many of the basic principles of protein structure and stability. For instance, the structure showed that when the protein chain folds into a globular structure, carbon-rich amino acids are sheltered inside and charged amino acids are most often found on the surface, occasionally forming salt bridges that pair two opposite charges (shown here with circles). To explore some of these principles, click on the image for an interactive JSmol.
Topics for Further Discussion
- You can use the sequence comparison tool to align the sequences of different myoglobins, looking for mutations. For instance, here is the alignment of whale and pig myoglobin used to create the illustration in this column.
- PDB entry 2jho includes myoglobin poisoned by cyanide. Take a look and you'll see that the cyanide blocks the binding site for oxygen.
Related PDB-101 Resources
- Browse Biomolecular Structural Biology
- Browse Biological Energy
- Browse Nobel Prizes and PDB structures
- 1mbn: J. C. Kendrew, R. E. Dickerson, B. E. Strandberg, R. G. Hart, D. R. Davies, D. C. Phillips & V. C. Shore (1960) Structure of Myoglobin. Nature 185, 422-427.
- J. C. Kendrew (1961) The three-dimensional structure of a protein molecule. Scientific American 205(6), 96-110.
- 1mbo: S. E. Phillips (1980) Structure and refinement of oxymyoglobin at 1.6 A resolution. Journal of Molecular Biology 142, 531-554.
- 1pmb: S. J. Smerdon, T. J. Oldfield, E. J. Dodson, G. G. Dodson, R. E. Hubbard & A. J. Wilkinson (1990) Determination of the crystal structure of recombinant pig myoglobin by molecular replacement and its refinement. Acta Crystallographica B, 46, 370-377.
- S. Mirceta, A. V. Signore, J. M. Burns, A. R. Cossins, K. L. Campbell & M. Berenbrink (2013) Evolution of mammalian diving capacity traced by myoglobin net surface charge. Science 340, 1234192.
January 2000, David Goodsellhttp://doi.org/10.2210/rcsb_pdb/mom_2000_1