Extended Data Fig. 2: Biochemical characterization of the metagenomic β-glucuronidase SN243.
From: Functional metagenomic screening identifies an unexpected β-glucuronidase
SN243 was most active on pNP-β-GlcA between pH 7.5 and 9.5. The buffer pH was varied between pH 4 and 11 using 100 mM citrate (pH 4-6), sodium phosphate (NaP, pH 6-8), Tris (pH 7.5-9), glycine (pH 9-10) and CAPS (pH 9.5-11) buffer, respectively, while keeping the salt concentration at 150 mM NaCl. (b) Thermostability of SN243. In a differential scanning fluorimetry experiment, the melting temperature of SN243 was determined at 62.6 °C. The assay was performed in triplicate. (c) Optimization of the reaction temperature. The temperature was increased in 2 °C increments and the initial reaction velocity with 10 nM SN243 and 50 μM pNP-β-GlcA recorded and normalized to the highest observed value (56 °C). (d) Determination of Michaelis-Menten kinetics at the optimal reaction temperature. Using 2 nM SN243, kinetic parameters for the reaction with pNP-β-GlcA were determined at 56 °C. The mean of three independent datasets and the standard errors with a 95% confidence level are shown.
