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Table 1 Kinetic parameters for ApV1 thermostable phytase compared to AppA phytase at 37 °C

From: Disulfide bond engineering of AppA phytase for increased thermostability requires co-expression of protein disulfide isomerase in Pichia pastoris

  Specific activity (103 U/g of protein)* KM (mM)* kcat (min−1)* kcat/KM (min−1 M−1)*
Phytic acid assay
 AppA phytase 1150 ± 138 0.83 ± 0.04 3.91 × 105 ± 0.51 × 105 3.47 × 108 ± 0.34 × 108
 ApV1 phytase 1273 ± 238 0.82 ± 0.04 2.65 × 105 ± 0.37 × 105 3.23 × 108 ± 0.28 × 108
p-NPP assay
 AppA phytase 1075 ± 40 10.63 ± 1.94 2.02 × 105 ± 0.64 × 105 1.57 × 107 ± 0.22 × 107
 ApV1 phytase 987 ± 42 11.34 ± 0.48 2.45 × 105 ± 0.13 × 105 1.72 × 107 ± 0.86 × 107
  1. *No significant statistical difference between phytases for phytic acid or p-NPP assays (p ≤ 0.05). Values correspond to biological triplicates of his-tag purified AppA and ApV1 phytases