TABLE 2

Enzyme kinetic parameters of the formation of MPAG and AcMPAG from MPA

Apparent Km, Vmax, and Ksi values for the formation of metabolites when MPA was incubated with diabetic and nondiabetic HLMs and HKMs, respectively.

NondiabeticDiabeticP Value
HLM incubations with MPA
    MPAG
        Vmax [pmol/(min · pmol P450)]10.6 ± 1.115.7 ± 0.54P = 0.046
        Km (μM)454.3 ± 95481.6 ± 35.1NS
        Vmax/Km [pl/(min · pmol P450)]22.9 ± 7.331.3 ± 9.2NS
        Ksi (μM)1.51.5
    AcMPAG
        Vmax [pmol/(min · pmol P450)]2.43 ± 0.030.76 ± 0.40P < 0.001
        Km (μM)601 ± 35502.3 ± 24.1NS
        Vmax/Km [pl/(min · pmol P450)]4.08 ± 0.051.51 ± 0.01P < 0.001
        Ksi (μM)2.02.0
HKM incubations with MPA
    MPAG
        Vmax [pmol/(min · pmol P450)]26.4 ± 0.738.8 ± 2.6P = 0.035
        Km (μM)1009 ± 1401158 ± 160NS
        Vmax/Km [pl/(min · pmol P450)]27.6 ± 5.234.1 ± 2.4NS
        Ksi (μM)1.51.5
    AcMPAG
        Vmax [pmol/(min · pmol P450)]1.17 ± 0.0010.43 ± 0.015P = 0.001
        Km (μM)3015 ± 2103431 ± 310NS
        Vmax/Km [pl/(min · pmol P450)]0.41 ± 0.070.12 ± 0.03P = 0.001
        Ksi (μM)2.02.0

  • pl, picoliter; NS, nonsignificant at P > 0.05; plus-minus values are mean ± S.E.