Kinetic parameters Vmax and KM of TNAP phosphatase assay: effect of mercaptopyruvate (MPA). At least 4 sets of experiments in duplicates were performed. Values are mean ± standard deviation.
MPA, μM | [Ca++] = [Mg++] = 0 mM | [Ca++] = [Mg++] = 1 mM | ||
---|---|---|---|---|
Vmax | KM | Vmax | KM | |
0 | 8.7 ± 1 | 6.1 ± 1 | 32 ± 10 | 41 ± 13 |
20 | 7.5 ± 1 | 5.8 ± 1 | 26 ± 8 | 33 ± 11 |
200 | 2.0 ± 0.1* | 9.1 ± 3* | 17 ± 1* | 19 ± 2* |
2000 | 1.5 ± 0.3* | 9.9 ± 5* | 10 ± 2* | 11 ± 3* |
↵* Calculated value with MPA present is statistically significantly different (p < 0.05) from the value with no MPA.