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Full-Text Articles in Physics
Human Glyoxalase Ii Contains An Fe(Ii)Zn(Ii) Center But Is Active As A Mononuclear Zn(Ii) Enzyme, Pattraranee Limphong, Ross M. Mckinney, Nicole E. Adams, Brian Bennett, Christopher A. Makaroff, Thusitha Gunasekera, Michael W. Crowder
Human Glyoxalase Ii Contains An Fe(Ii)Zn(Ii) Center But Is Active As A Mononuclear Zn(Ii) Enzyme, Pattraranee Limphong, Ross M. Mckinney, Nicole E. Adams, Brian Bennett, Christopher A. Makaroff, Thusitha Gunasekera, Michael W. Crowder
Physics Faculty Research and Publications
Human glyoxalase II (Glx2) was overexpressed in rich medium and in minimal medium containing zinc, iron, or cobalt, and the resulting Glx2 analogues were characterized using metal analyses, steady-state and pre-steady-state kinetics, and NMR and EPR spectroscopies to determine the nature of the metal center in the enzyme. Recombinant human Glx2 tightly binds nearly 1 equiv each of Zn(II) and Fe. In contrast to previous reports, this study demonstrates that an analogue containing 2 equiv of Zn(II) cannot be prepared. EPR studies suggest that most of the iron in recombinant Glx2 is Fe(II). NMR studies show that Fe(II) binds to …
Structure And Mechanism Of Copper- And Nickel-Substituted Analogues Of Metallo-Β-Lactamase L1, Zhenxin Hu, Lauren J. Spadafora, Christine E. Hajdin, Brian Bennett, Michael W. Crowder
Structure And Mechanism Of Copper- And Nickel-Substituted Analogues Of Metallo-Β-Lactamase L1, Zhenxin Hu, Lauren J. Spadafora, Christine E. Hajdin, Brian Bennett, Michael W. Crowder
Physics Faculty Research and Publications
In an effort to further probe metal binding to metallo-β-lactamase L1 (mβl L1), Cu- (Cu-L1) and Ni-substituted (Ni-L1) L1 were prepared and characterized by kinetic and spectroscopic studies. Cu-L1 bound 1.7 equiv of Cu and small amounts of Zn(II) and Fe. The EPR spectrum of Cu-L1 exhibited two overlapping, axial signals, indicative of type 2 sites with distinct affinities for Cu(II). Both signals indicated multiple nitrogen ligands. Despite the expected proximity of the Cu(II) ions, however, only indirect evidence was found for spin−spin coupling. Cu-L1 exhibited higher kcat (96 s−1) and Km (224 μM) values, as …