Figure 3.
Kinetic parameters of Hyb-24 mutant enzymes. Ald-hydrolytic activity was assayed using the His-tagged enzymes under standard assay conditions, except that various concentrations of Ald were used. Kinetic parameters (kcat and Km values) were evaluated by directly fitting the Michaelis–Menten equation to the data using GraphPad prism, version 5.01 (GraphPad, San Diego, CA). The kcat values were expressed as turnover numbers per subunit (Mr of the subunit: 42,000). The kinetic parameters of Hyb-24Y and Hyb-24DNY reported previously (18) are shown for comparison. Shaded box, polypeptide regions from NylB; open box, region from NylB′. Amino acid alterations are shown as one-letter codes in the box.