TABLE 2

Kinetic determinations for wild-type and mutant forms of PTP4A3

The kinetic parameters were determined with wild-type and mutant forms of recombinant human PTP4A3 and the artificial substrate DiFMUP. N = 3, mean ± S.E.M.

ParameterPTP4A3PTP4A3 C49SPTP4A3 K144IPTP4A3 A106VPTP4A3 A111S
Km (μM)4.04 ± 0.5941.10 ± 9.014.73 ± 0.7132.04 ± 6.8818.94 ± 6.16
Kcat (min−1)5.77 ± 0.534.93 ± 0.246.47 ± 0.698.51 ± 2.1438.72 ± 6.78
Kcat/Km (min−1/μM−1)1.50 ± 0.530.13 ± 0.031.40 ± 0.240.26 ± 0.012.21 ± 0.46