Kong L M, Qian M R, Hu H H, Xu S Y, Yu L S, Jiang H D, Chen S Q, Zeng S
College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, PR China.
Pharmazie. 2012 May;67(5):440-7.
Polymorphisms of the cytochrome P450 2D6 (CYP2D6) gene play a major role in pharmacokinetic variability in human, while CYP2D6*10 is an important subtype in Asian people. In this study, the co-expression enzyme of human recombinant CYPOR, CYPb5 and CYP2D6.1 or CYP2D6.10 with the Bac-to-Bac system in baculovirus-infected insect cells was used to study the catalytical activity to imipramine metabolism and stereoselective metabolism of propranolol. The metabolites of imipramine were identified of hydroxyl imipramine and desipramine by LC-MS/MS. There are some differences between CYP2D6.1 and CYP2D6.10 activity. The kinetics parameters K(m), V(max), and CL(int) are 11.77 +/- 0.91 micromol/L, 0.4235 +/- 0.05 nmol/nmol CYP2D6.1/min and 3.60 x 10(-5) ml/min/nmol CYP2D6.1 (n = 3) for CYP2D6.1, respectively, and 9.05 +/- 0.87 micromol/L, 0.42 +/- 0.03 nmol/nmol CYP2D6.10/min, and 4.60 x 10(-5) ml/min/nmol CYP2D6.10 (n = 3) for CYP2D6.10. For propranolol, two metabolites were identified to be hydroxyl and N-desisopropylation propranolol by LC-MS/MS. When the substrate concentration was 0.20 micromol/L, CYP2D6.1 and CYP2D6.10 exhibited significant stereoseletivity. Furthermore, enantioselective formation has been detected. Both of CYP2D6.1 and CYP2D6.10 produced more hydroxyl propranolol from the R-(+)-isomer than from the S-(-)-isomer while there was no obvious difference for N-desisopropylation propranolol production between R-(+)- and S-(-)- isomer. In summary, there is a somewhat different catalytical activity and stereoselectivity between the human recombinant CYP2D6.1 and CYP2D6.10. The data we got will be helpful in preclinical research and clinical use of CYP2D6 substrates.
细胞色素P450 2D6（CYP2D6）基因多态性在人类药代动力学变异性中起主要作用，而CYP2D6*10是亚洲人群中的一种重要亚型。在本研究中，利用杆状病毒感染昆虫细胞中的Bac-to-Bac系统共表达人重组CYPOR、CYPb5和CYP2D6.1或CYP2D6.10，以研究其对丙咪嗪代谢的催化活性和普萘洛尔的立体选择性代谢。通过LC-MS/MS鉴定出丙咪嗪的代谢产物为羟基丙咪嗪和地昔帕明。CYP2D6.1和CYP2D6.10的活性存在一些差异。CYP2D6.1的动力学参数K(m)、V(max)和CL(int)分别为11.77±0.91μmol/L、0.4235±0.05nmol/nmol CYP2D6.1/min和3.60×10(-5)ml/min/nmol CYP2D6.1（n = 3），CYP2D6.10的分别为9.05±0.87μmol/L、0.42±0.03nmol/nmol CYP2D6.10/min和4.60×10(-5)ml/min/nmol CYP2D6.10（n = 3）。对于普萘洛尔，通过LC-MS/MS鉴定出两种代谢产物为羟基普萘洛尔和N-去异丙基普萘洛尔。当底物浓度为0.20μmol/L时，CYP2D6.1和CYP2D6.10表现出显著的立体选择性。此外，还检测到了对映体选择性形成。CYP2D6.1和CYP2D6.10从R-(+)-异构体产生的羟基普萘洛尔均多于S-(-)-异构体，而R-(+)-和S-(-)-异构体之间N-去异丙基普萘洛尔的产生没有明显差异。总之，人重组CYP2D6.1和CYP2D6.10之间的催化活性和立体选择性存在一定差异。我们获得的数据将有助于CYP2D6底物的临床前研究和临床应用。
