tailieunhanh - Báo cáo khoa học: Engineering and characterization of human manganese superoxide dismutase mutants with high activity and low product inhibition

Human manganese superoxide dismutase is a mitochondrial metalloenzyme that is involved in protecting aerobic organisms against superoxide toxicity, and has been implicated in slowing tumor growth. Unfortunately, this enzyme exhibits strong product inhibition, which limits its potential bio-medical applications. | ỊFEBS Journal Engineering and characterization of human manganese superoxide dismutase mutants with high activity and low product inhibition Karuppiah Chockalingam1 James Luba2 Harry S. Nick3 David N. Silverman2 and Huimin Zhao1 1 Departments of ChemicalEngineering and Biomolecular Engineering and Chemistry Institute for Genomic Biology Center for Biophysics and ComputationalBiology University of Illinois at Urbana-Champaign Urbana IL USA 2 Department of Pharmacology and Biochemistry University of Florida Gainesville FL USA 3 Department of Neuroscience University of Florida Gainesville FL USA Keywords directed evolution gene therapy kinetic analysis product inhibition Correspondence D. N. Silverman Department of Pharmacology and Biochemistry University of Florida Gainesville FL 32610 USA Fax 1 352 392 9696 Tel 1 352 392 3556 E-mail Silvermn@ H. Zhao Departments of Chemical Engineering and Biomolecular Engineering and Chemistry Institute for Genomic Biology Center for Biophysics and ComputationalBiology University of Illinois at Urbana-Champaign Urbana IL61801 USA Fax 217 333 5052 Tel 1 217 333 2631 E-mail zhao5@ These authors contributed equally to this work Received 27 June 2006 revised 23 August 2006 accepted 30 August 2006 doi Human manganese superoxide dismutase is a mitochondrial metalloenzyme that is involved in protecting aerobic organisms against superoxide toxicity and has been implicated in slowing tumor growth. Unfortunately this enzyme exhibits strong product inhibition which limits its potential biomedical applications. Previous efforts to alleviate human manganese superoxide dismutase product inhibition utilized rational protein design and site-directed mutagenesis. These efforts led to variants of human manganese superoxide dismutase at residue 143 with dramatically reduced product inhibition but also reduced catalytic activity and efficiency. Here we report the use of a directed evolution