Figure 7.

Thermal inactivation assay of purified wild-type Lsc3 and the mutant proteins Asp31Asn, Glu236Gln, Val248Ala, Thr302Met and Thr302Pro. After incubation of 5 μM of a levansucrase in McIlvaine’s buffer (pH 6.0) at a selected temperature, its residual activity was measured according to release of glucose from 100 mM sucrose [4]. The activity of a preparation kept at 20 °C was used as reference for 100% of activity. Inner panel shows T_m values obtained by the Thermofluor assay. The mean values of at least two parallel experiments and respective standard deviations are shown.