Fig. 2

Enzymatic properties of the purified recombinant wild-type XylE and its hybrid mutants. a pH activity profiles tested at the optimal temperature for each enzyme (70 °C for XylE, XylE-M9, XylE-M3/M9, and XylE-M6/M9; and 75 °C for the others). b pH stability profiles. After incubation of the enzymes at 37 °C for 1 h in buffers ranging from pH 1 to 10, the residual activities were determined in 100 mM McIlvaine buffer at the optimal pH and optimal temperature of each enzyme. c Temperature activity profiles tested at the optimal pH of each enzyme (pH 4.5 for XylE and pH 5 for the others). d Temperature stability profiles (T₅₀). e Thermograms determined by using DSC. The calorimetric recordings for XylE and its mutants were scanned at 1 °C/min in 10 mM phosphate-buffered saline (PBS) (pH 6.5) at 350 µg/mL. f Half-lives of wild-type XylE and its mutants at 65 °C