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.
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
- De Rienzo F, Gabdoulline RR, Menziani MC, Wade RC (2000). "Blue copper proteins: a comparative analysis of their molecular interaction properties.". Protein Sci 9 (8): 1439–54. doi:10.1110/ps.9.8.1439. PMID 10975566.
- Tohru Yamada,1 Masatoshi Goto,1 Vasu Punj, Olga Zaborina, Kazuhide Kimbara, T. K. Das Gupta,and A. M. Chakrabarty1 (Dec 2002). "The Bacterial Redox Protein Azurin Induces Apoptosis in J774 Macrophages through Complex Formation and Stabilization of the Tumor Suppressor Protein p53". Infect Immun. 70 (12): 7054–7062. doi:10.1128/IAI.70.12.7054-7062.2002. PMC 133031. PMID 12438386.