Quality-control method for the determination of biological activity of engineered calcineurin subunit B

Abstract

The aim of this study was to establish a quality-control method for calcineurin subunit B (CNB) biological activity determinations. CNB enhances the p-nitrophenylphosphate (pNPP) dephosphorylating activity of calcineurin subunit A Δ316 mutant (CNAΔ316). A series of CNB concentrations were fitted to a four-parameter equation to calculate the corresponding pNPP maximum dephosphorylation rates. Values were calculated based on biological activity references using a parallel line method. The method was then validated for accuracy, precision, linearity, linear range, sensitivity, specificity, and robustness. The recovery results were greater than 98%. Intra-plate precision was 6.7%, with inter-plate precision of 10.8%. The coefficient of determination was greater than 0.98. The linear range was 0.05-50 μg mL 1 , with sensitivity of 50 μg mL 1 . Tested cytokines did not induce CNAΔ316 dephosphorylation of pNPP. The chosen CNAΔ316 concentration range did not affect activity determinations.calcineurin subunit B, biological activity, method establishment, method validation, quality control Citation: