Published on Web 11/15/2006
Reduction Potential Tuning of the Blue Copper Center in Pseudomonas aeruginosa Azurin by the Axial Methionine as Probed by Unnatural Amino Acids Dewain K. Garner,† Mark D. Vaughan,‡ Hee Jung Hwang,† Masha G. Savelieff,† Steven M. Berry,† John F. Honek,*,‡ and Yi Lu*,† Contribution from the Department of Chemistry, UniVersity of Illinois at Urbana-Champaign, Urbana, Illinois 61801 and the Department of Chemistry, UniVersity of Waterloo, Waterloo, Ontario, Canada N2L 3G1 Received April 19, 2006; E-mail:
[email protected];
[email protected] Abstract: The conserved axial ligand methionine 121 from Pseudomonas aeruginosa azurin (Az) has been replaced by isostructural unnatural amino acid analogues, oxomethionine (OxM), difluoromethionine (DFM), trifluoromethionine (TFM), selenomethionine (SeM), and norleucine (Nle) using expressed protein ligation. The replacements resulted in
