Document Type
Article
Rights
Available under a Creative Commons Attribution Non-Commercial Share Alike 4.0 International Licence
Disciplines
1.6 BIOLOGICAL SCIENCES, Biochemistry and molecular biology, Biochemical research methods
Abstract
Horseradish Peroxidase (HRP) has long attracted intense research interest and is used in many biotechnological fields, including diagnostics, biosensors and biocatalysis. Enhancement of HRP catalytic activity and/or stability would further increase its usefulness. Based on prior art, we substituted solvent-exposed lysine and glutamic acid residues near the proximal helix G (Lys 232, 241; Glu 238, 239) and between helices F and F’ (Lys 174). Three single mutants (K232N, K232F, K241N) demonstrated increased stabilities against heat (up to two-fold) and solvents (up to four-fold). Stability gains are likely due to improved hydrogen bonding and space-fill characteristics introduced by the relevant substitution. Two double mutants showed stability gains but most double mutations were non-additive and non-synergistic. Substitutions of Lys 174 or Glu 238 were destabilising. Unexpectedly, notable alterations in steady-state Vm/E values occurred with reducing substrate ABTS (2,2’-azino-bis(3- ethylbenzthiazoline-6-sulfonic acid)), despite the distance of the mutated positions from the active site.
DOI
https://doi.org/10.1016/j.biochi.2008.05.008
Recommended Citation
Ryan, B. & Ó Fágáin, C. (2007). Effects of mutations in the Helix G region of Horseradish Peroxidase. Biochemie, vol. 89,(8), pp.1029-1032. doi:10.1016/j.biochi.2008.05.008
Funder
Embark Initiative and Dublin City University
Publication Details
Biochimie, 89, (8), 1029-1032.