抑制細胞色素P450 3A4表面電漿共振生物晶片應用於藥物篩選之研發

The Development of SPR Biochip for Drug Screening based on Inhibition of Cytochrome P450 3A4

廖冠喬(Kwan-Chiao Liao)

指導教授 ： 林啟萬

國立臺灣大學/工學院/醫學工程學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.02803

摘要

細胞色素P450為人體內主要代謝外來物及藥物的主要酵素，其功能為利用鐵離子來氧化外來物，使其變成具親水性並可以隨人體的代謝而排出體外。若人體內的細胞色素P450被抑制會造成嚴重的不良反應。因此，量測細胞色素P450抑制程度是個很重要的研究方向，並且可以應用在藥物篩選以及藥物與藥物之間的交互作用研究。

本論文利用表面電漿共振感測器來量測細胞色素P450抑制試驗。表面電漿共振感測器是一種光學式的生物感測器可用於生物分子交互作用的量測。具有高靈敏度、免螢光標的、即時監控和大量平行篩選等優點，比傳統上利用螢光方法量測更具競爭性與優勢。

在本論文實驗中，已成功將細胞色素P450固定於金膜上並可以量測到P450與受質DBOMF的反應，此受質催化後會發出波長520nm螢光，其解離常數為0.0161 uM。選用ketoconazole為P450抑制物，可成功量測其半數抑制濃度(IC50)為0.16uM。氣體幫浦的自動化，可以加速檢測試驗的速度並節省人力。未來希望能夠整合以上成果，開發出自動化的藥物篩選平台。

相信這是第一次用表面電漿共振來量測細胞色素P450的抑制測試

關鍵字

細胞色素P450 ； 表面電漿共振 ； 生物晶片 ； 藥物篩選

並列摘要

Cytochrome P450 is the major enzyme that metabolizes xenobiotic and drugs in human body. The basic purpose of drug metabolism is to make drugs more water soluble by Fe3+ and thus more readily excreted in the urine. Inhibition of cytochrome P450 will cause adverse drug reaction. It is thus important to measure the inhibition of cytochrome P450 by drugs and extending into drug screening for drug-drug interactions.

The inhibition of cytochrome P450 is measured by surface plasmon resonance (SPR), which is an optical sensing mechanism for biomolecular interactions, in this thesis. It has advantages of high sensitive, non-labeling, and real-time monitoring, comparing to the other sensing methods.

Cytochrome P450 is immobilized on gold chip to measure the enzyme kinetics by the interaction with substrate DBOMF which is metabolized by P450 3A4 into fluorescent product emission at 520nm. by SPR. The resultant dissociation constant Kd is about 0.0161 uM. Choose ketoconazole as P450 inhibitor, the 50% inhibitory concentration (IC50) is found about 0.16 uM.

Automation of gas pump can improve the efficiency of screening process.
It is our believe that this is the first time SPR is applied toward the measurement of CYP450 for such a purpose.

並列關鍵字

Cytochrome P450 ； SPR ； biochip ； drug screening

參考文獻

[1] Bertz RJ, Granneman GR. Use of in vitro and in vivo data to estimate the likelihood of metabolic pharmacokinetic interactions. Clin Pharmacokinet. Mar 32 (3) 210-58 (1997).

[2] Charles L. Crespi, Vaughn P. Miller. The use of heterologously expressed drug metabolizing enzymes—state of the art and prospects for the future. Pharmacology & Therapeutics 84 121–131(1999).

[3] Shimada T, Yamazaki H, Mimura M et al. Interindividual variation in human liver cytochrome P450 enzymes involved in the oxidation of drugs, carcinogens, and toxic chemical, J. Pharmacol. Exp. Ther. 270 414-423 (1994).

[4] Zhengyin Yan and Gary W. Caldwell. Metabolism Profiling and Cytochrome P450 Inhibition & Induction in Drug Discovery. Current Topics in Medicinal Chemistry 403 1 403-425 (2001).

[5] Larry C. Wienkers and Timothy G. Heath. Predicting in VIVO Drug Interaction From in VITRO Drug Discovery Data. Nature Review Drug Discovery OCTOBER 4 825-833 (2005).