https://orcid.org/0000-0002-7922-1062
Figures & data
Figure 1. Identification of expressed UGT1A proteins using western blotting, maximum velocity of each wildtype UGT1A protein (A), and Michaelis–Menten kinetics of SN-38 glucuronidation by the expression of each wildtype UGT1A protein (B). (A) The relative expression levels of each of the UGT1A protein were determined using western blotting with mouse anti-human UGT1A antibody and m-IgG k BP-HRP. Approximately 55-kDa protein bands were detected in all expression models and UGT1A-positive proteins. The columns indicate the maximum velocity of each wildtype of UGT1A protein for SN-38 glucuronidation. The reaction mixture contained 15 μL cell homogenate and 2 mM UDPGA; it was incubated at 37 °C for 1 h at pH 7.4. SN-38 concentrations ranged from 0.1 to 2.0 mM. (B) The line indicates the fitting of the data to the Michaelis–Menten equation using non-linear regression. The reaction mixture contained 15 μL cell homogenate and 2 mM UDPGA; it was incubated at 37 °C for 1 h at pH 7.4. SN-38 concentrations ranged from 0.1 to 2.0 mM. PC: positive control; †p < 0.05 compared with wildtype UGT1A1.
Figure 2. Identification of the expression of each of the UGT1A protein (wildtype and major variant proteins) using western blotting and Michaelis–Menten kinetics of SN-38 glucuronidation, expressed by each wildtype and major variants of UGT1A proteins. The relative expression levels of each of the UGT1A protein were determined using western blotting with mouse anti-human UGT1A antibody and m-IgG k BP-HRP. Approximately 55-kDa protein bands were detected in all wildtype and polymorphic UGT1A proteins. The line indicates the fitting of the data to the Michaelis–Menten equation using non-linear regression. The reaction mixture contained 15 μL cell homogenate and 2 mM UDPGA; it was incubated at 37 °C for 1 h at pH 7.4. SN-38 concentrations ranged from 0.1 to 2.0 mM.
Table 1. Catalytic activity of each UGT1A.1 isoform.
Table 2. Catalytic activity of each UGT1A variant.
Supplemental Material
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The data that support the findings of this study are available from the corresponding author, Y. M., upon reasonable request.
