Fig 3. TLC analysis of the activities of deletion constructs and site-directed mutants towards Ara₃-Hyp-DNS.

The reaction was performed in a solution containing 50 μM Ara₃-Hyp-DNS (substrate) and 50 mM Na-acetate buffer (pH 5.5). After development, the fluorescence of the dansyl group was detected. (Left) The substrate was incubated either without (lane 1) or with the deletion constructs (lanes 2 and 3, 0.45 mg/ml protein) at 30°C for 20 min. Lane 2, CΔ1049; lane 3, CΔ789. (Right) The substrate was incubated either without (lane 4), with CΔ1049 (lane 5, 2.5 mg/ml protein), or with site-directed point mutants of CΔ1049 (lanes 6–11, 2.5 mg/ml protein) at 37°C for 1 h. Lane 6, D515A; lane 7, D515N; lane 8, E713A; lane 9, E713Q; lane 10, E383A; lane 11, E383Q.