Figure 3.

General properties of the recombinant AtGCD3. A, pH dependence of glucosylceramidase activity of purified AtGCD3. To vary the pH, 50 mm sodium acetate buffer (pH 4.0–5.5), MES (pH 5.5–6.5), sodium phosphate buffer (pH 6.5–7.5), or HEPES buffer (pH 7.5–8.0) were used. B, optimal temperature. Assay mixtures were incubated at 15–60 °C. C, effects of DMSO on AtGCD3 activity. D, metal ion dependence of AtGCD3 activity. Assay mixtures were incubated with a 1 mm concentration of the indicated metal ions. Data represent the mean ± S.D. (error bars) (n ≥ 3) of independent experiments.