User:Czeer/sandbox 5

Facts

 * Azurin is a blue copper protein. The blue copper proteins are redox active, and bright blue due to an electron transfer to the metal centre (citation?).
 * Azurin homologues have similar structures, however different redox potentials.
 * Pseudomonas aeruginosa is a small 128 residue copper binding protein.
 * In P aeruginosa azurin, the electron transfer that gives rise to the bright blue colour is thought to arise partly from a structural disulfide bond near the redox active copper..
 * Azurin might enable electron transfer to different systems, including "denitrification and/or respiratory chains", and possibly in response to oxidative stress.
 * One alpha helix, with eight beta-strands that fold into two beta sheets with a greek key beta barrel topology.
 * In P. aeruginosa copper is coordinated in an trigonal bipyramidal geometry, equatorially through two histidine and a cysteine residue, and axially through a methionine and main-chain carbonyl residue.
 * P aeruginosa absorbs at 625 nm (ε=5, 700 M-1 cm-1) and 410 nm (ε=10,000 M-1cm-1)

http://onlinelibrary.wiley.com/doi/10.1002/advs.201400026/references

http://link.springer.com/article/10.1007%2Fs007750000146

Azurin is a bacterial blue copper protein found in Pseudomonas, Bordetella, or Alcaligenes bacteria, which undergoes oxidation-reduction between Cu(I) and Cu(II), and transfers single electrons between enzymes associated with the cytochrome chain. The protein has a molecular weight of approximately 16,000, contains a single copper atom, is intensively blue, and has a fluorescence emission band centered at 308nm.

Azurins and pseudoazurins participate in denitrification processes in bacteria.

Azurin and cytochrome c551 are involved in electron transfer during denitrification in P. aeruginosa. Azurin from P aeruginosa is a type I blue copper protein with a molecular mass of 14 kDa, while cytochrome c551 (9 kDa) is a haem-containing cytochrome. Azurin possesses a relatively large hydrophobic patch close to the active site, and two residues in this hydrophobic patch, Met-44 and Met-64, are believed to be involved in its interaction with the redox partners cytochrome c551 and nitrite reductase