Skip to main content

Table 3 Stability Characteristics of HRP Immobilisation Mutants in free solution and immobilised on CNBr-activated Sepharose

From: Arginine-to-lysine substitutions influence recombinant horseradish peroxidase stability and immobilisation effectiveness

  Thermal Stability Solvent and H2O2 Stability
Mutant T50 (°C) k-value (min-1) SD (min-1) t1/2 (min) DMSO C50 MeOH C50 DMF C50 H2O2 C50
Free Solution         
WT 50 0.0559 ± 0.0034 12 35 53 14 17
Mutant 1 51 0.0535 ± 0.0005 12 34 44 12 38
Mutant 2 50 0.0568 ± 0.0057 12 30 35 16 44
Mutant 3 48 0.0109 ± 0.0007 6 35 45 25 17
Mutant 4 50 0.0445 ± 0.0003 17 30 35 16 33
Immobilised         
WT - 0.0255 ± 0.0023 27 32 40 14 6
Mutant 1 - 0.0223 ± 0.0020 3 24 32 17 5
Mutant 2 - 0.0544 ± 0.0044 13 28 38 10 5
Mutant 3 - 0.0152 ± 0.0017 5 42 43 29 5
Mutant 4 - 0.0491 ± 0.0049 14 28 38 15 5
  1. WT, Wildtype; Mutant 1, R118K/R159K/R283K; Mutant 2, R118K/R159K; Mutant 3, R118K/R159K/K232N/K241F/R283K; Mutant 4, R118K/R159K/K232N/K241F. Modelled k-values were calculated using the Enzfitter™ software package (Version 1.05. Cambridge UK: Biosoft Ltd.; 1987). Values are the mean of three independent determinations in each case. Standard deviations were < 5% for solvent and < 10% for H2O2 studies. Units of C50 are % v/v for solvents and mM for H2O2.