@article{ajmbr2016432,
author={{Ufot, Usenobong F. and Ite, Aniefiok E. and Usoh, Idorenyin H. and Akpanabiatu, Monday I.},
title={Role of Some Metal Ions on Steady¨Cstate Kinetics of Engineered Wild¨Ctype and Manganese (II) Binding Site Mutants of Recombinant Phlebia radiata Manganese Peroxidase 3 (rPr-MnP3)},
journal={American Journal of Medical and Biological Research},
volume={4},
number={3},
pages={42--52},
year={2016},
url={http://pubs.sciepub.com/ajmbr/4/3/2},
issn={2328-4099},
abstract={This study investigated the steady-state kinetics of engineered wild-type and manganese (II) binding site mutants of recombinant Phlebia radiata manganese peroxidase 3(rPr-MnP3). The effect (activation or inhibition) of some metal ions (Co2+, Zn2+ Cu2+ and Na+) on the activity of rPr-MnP3 enzymes was also studied. The results obtained showed that the rPr-MnP3 mutants in which the metal binding functionality has been largely lost have been created. Na+ (mono-valent ion) and Co2+showed similar characteristics by exhibiting stimulatory effects on the activity of wild-type rPr-MnP3. However, Cu2+ and Zn2+ had mixed inhibitory effects on wild-type and mutants (E40H, E44H, E40H/E44H). It was observed that Cu2+ was by far the strongest inhibitor of engineered rPr-MnP3 enzymes while Co2+ exhibited a non-competitive inhibitory effect on the double mutant (E40H/E44H) and D186H activities. In addition, Zn2+ and Cu2+also had non-competitive inhibitory effect on D186H mutant enzyme activity. The results obtained further showed that the competitive inhibitory effect of Cu2+observed in other rPr-MnP3 enzymes is largely removed in D186H mutant enzyme. Generally, histidine substitution retained a strong selectivity for Cu2+ as competitive inhibitor. Zn2+ being generally non-competitive suggest involvement of sites other than the Mn (II) binding site. This study showed that rPr-MnP3 enzymes function with alternate ligands in the Mn2+ binding site and does not have absolute obligate requirement for all carboxylate ligand set.},
doi={10.12691/ajmbr-4-3-2}
publisher={Science and Education Publishing}
}