Elizeu/sandbox/citocromo c
From Proteopedia
The Structure Function Relationship of Haemoglobin
Introduction
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Haemoglobin is a tetrameric globular protein able to transport small molecules such as oxygen and carbon dioxide around the body to support life. Its a great example of how a protein's binding affinity to its ligand can change in response to changes in its environment. This is facilitated by small conformational changes that occur in and between subunits in a cooperative manner ultimately allowing O2 to be picked up in the lungs and delivered to the tissues.
Exploring the Structure
Haemoglobin (Hb) consists of 2 identical &alpha subunits and 2 identical &beta subunits. The strongest inter-subunit interactions exist between the &alpha and &beta subunits so Hb could be considered to be a dimer of &alpha/&beta subunits. The α subunits have 141 residues while &beta subunits have 146 residues. Each monomer contains a haeme prosthetic group facilitating O2 coordination.
On the right is . Embedded in each monomer is the haeme prosthetic group with bound (ferrous) iron. Iron makes 6 coordination bonds. Four in the plane of the haeme to 4 nitrogens (blue); one to the proximal Histidine imidizole nitrogen and one reserved for oxygen.
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Julie Langlois, Atena Farhangian, Rebecca Holstein, Elizabeth A. Dunlap, Katherine Reynolds, Elizeu Santos, Noam Gonen, Anna Lohning, Idan Ben-Nachum, Brian Ochoa, Shai Biran, Gauri Misra, Shira Weingarten-Gabbay, Keni Vidilaseris, Jamie Costa, Abhinav Mittal, Urs Leisinger, Madison Walberry, Edmond R Atalla, Brett M. Thumm, Brooke Fenn, Joel L. Sussman, Mati Cohen, Vesta Nwankwo, Dotan Shaniv, Gulalai Shah
