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. Author manuscript; available in PMC: 2009 Apr 1.
Published in final edited form as: Biotechnol Lett. 2007 Nov 8;30(4):671–676. doi: 10.1007/s10529-007-9588-y

Table 2.

Apparent kinetic parameters of Pd2,6STsa

Enzymes Δ15Pd2,6ST(N) Δ112Pd2,6ST(N)
Substrates CMP-Neu5Ac LacMU CMP-Neu5Ac LacMU
KM (mM) 0.9 ± 0.2 0.8 ± 0.1 0.9 ± 0.3 0.6 ± 0.1
Vmax (mMs−1) (4.6 ± 0.4) × 10−4 (4.0 ± 0.2) × 10−4 (4.2 ± 0.3) × 10−4 (3.4 ± 0.2) × 10−4
kcat (s−1) 2.7 ± 0.2 2.3 ± 0.1 1.4 ± 0.1 1.1 ± 0.1
kcat/KM (s−1 mM−1) 2.9 3.0 1.6 1.9
a

Assays were performed in duplicate in a reaction mixture of 20 μl containing Tris-HCl buffer (100 mM, pH 8.5) using varied concentrations (0.1, 0.25, 0.4, 1, 2, and 4 mM) of LacMU and a fixed concentration (1 mM) of CMP-Neu5Ac, or a fixed concentration (1 mM) of LacMU and varied concentrations (0.1, 0.25, 0.4, 1, 2, and 4 mM) of CMP-Neu5Ac. The amount of Δ15Pd2,6ST(N) used was 190 ng, and the amount of Δ112Pd2,6ST(N) used was 285 ng. Reactions were allowed to proceed for 30 min at 37 °C. Apparent kinetic parameters were obtained by fitting the data (the average values of duplicate assay results) into the Michaelis-Menten equation using Grafit 5.0.