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Effects of mutations in the helix G region of horseradish peroxidase
- Source :
-
Biochimie . Sep2008, Vol. 90 Issue 9, p1414-1421. 8p. - Publication Year :
- 2008
-
Abstract
- 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 2-fold) and solvents (up to 4-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 V m/E values occurred with reducing substrate ABTS (2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)), despite the distance of the mutated positions from the active site. [Copyright &y& Elsevier]
- Subjects :
- *METALLOENZYMES
*HORSERADISH
*ETHYLENE glycol
*RADIOGENETICS
Subjects
Details
- Language :
- English
- ISSN :
- 03009084
- Volume :
- 90
- Issue :
- 9
- Database :
- Academic Search Index
- Journal :
- Biochimie
- Publication Type :
- Academic Journal
- Accession number :
- 33389348
- Full Text :
- https://doi.org/10.1016/j.biochi.2008.05.008