| Budget Amount *help |
¥17,410,000 (Direct Cost: ¥15,400,000、Indirect Cost: ¥2,010,000)
Fiscal Year 2007: ¥8,710,000 (Direct Cost: ¥6,700,000、Indirect Cost: ¥2,010,000)
Fiscal Year 2006: ¥8,700,000 (Direct Cost: ¥8,700,000)
|
|---|
| Research Abstract |
In this study, we focused on cytochrome P450 (CYP) which is a dominant group in the human drug metabolizing enzymes, and we aimed at the establishment of a clinical principle which is applicable to order-made treatment, through comprehensive studies on the drug binding and metabolizing activities of mutants which are prepared on the bases of the information on human genomic single-nucleotide polymorphisms (SNPs). We prepared CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4, along with mutants of these CYPs based on the SNP information, and measured drug metabolizing properties of these CYPs. In addition, we measured resonance Raman spectra of them in order to clarify structural factors that are affected by SNPs. Furthermore, we measured drug metabolizing properties of the mutants in order to investigate the effect of SNPs. We could establish that a parameter Kd, which is an index of drug binding affinity, is linearly correlated with Km, a measure of metabolizing activity. In addition, Vmax was found to linearly correlate with the content of 5-coordinated heme. Because the value Vmax/Km is correlated with drug clearance, it is now clear that static values of Kd and 5-coordination reveals the drug clearance. On the other hand, we succeeded in the preparation of CYP3A4 and CYP2D6 by adding a substrate drug to stabilize the protein, and modifying surfactants during the purification step. Thus, we finally established that drug metabolism by CYPs can be conprehensively investigated using these CYPs.
|
