What are the different classifications of proteins?
Globular, fibrous, and membrane proteins
A monomeric, globular protein composed of 123 amino acids. Contains the prosthetic group haem.
Only two polar residues on the interior; two histidine residues.
What does haem consist of?
Protoporphyrin IX and a central iron atom. The protoporphyrin is made up of four pyrrole rings linked by methine bridges to form a tetra-pyrrole ring.
Which iron state in haem is capable of binding oxygen?
The ____ in haem can form two additional bonds, one each side of the ____ _____. These binding sites are called the _____ and _____ coordination sites.
The iron in haem can form two additional bonds, one each side of the haem plane. These binding sites are called the fifth and sixth coordination sites.
In myoglobin, the _____ coordination site is occupied by the _______ ring of a ________ residue from the protein. The ________ is referred to as the proximal ________.
In myoglobin, the fifth coordination site is occupied by the imidazole ring of a histidine residue from the protein. The histidine is referred to as the proximal histidine.