泊松-能斯特-普朗克-費米理論的CaVab通道數值結果

Numerical Results of CaVab Channels by Poisson–Nernst–Planck–Fermi Theory

黃永智(Yung-Chih Huang)

指導教授 ： 劉晉良

國立清華大學/理學院/應用數學系所/碩士(2017年)

摘要

動物細胞上有無數的離子通道，每種通道會控制細胞膜電壓差異並允許對應的離子通過，藉此維持生理功能正常。由於離子通道實在太小了，要觀察並記錄它的各種數據需要大量的時間和昂貴的設備，因此我們使用
泊松-能斯特-普朗克-費米 (PNPF) 模型模擬陽離子通過此通道時的情形。
該方法能分析通道蛋白質通道內的分子表面、奇異電荷並展現出模擬離子流動情形上的重要特徵，如最佳集中、有效率的非線性迭代和物理特性。PNPF 模型模擬 CaVab 通道在不同電壓下所產生的電流與實驗的電流-電壓取得數據上的一致。另一個模擬方法 MOL 則是將通道內重要的點位加上離子，經過計算後得出離子是否在該位置會穩定存在，用以展現出CaVab 通道的推擠與離子進出細胞的方式，在結果上也與實現數據相當的吻合。

關鍵字

鈣離子通道

並列摘要

Animal cells have numerous ion channels, each channel controls cellular membrane voltage difference and allows corresponding ions to pass through the channel by this way to keep the normal physiological function. Because the size of ion channels is too tiny, observing and recording its various data needs a lot of time and expensive equipment. Because of that, we simulate the cation transport through CaVab by using the Poisson-Nernst-Planck-Fermi (PNPF) model. The method can analyze molecular surfaces and singular charges of channel proteins and exhibit important features in flow simula-tions such as optimal convergence, efficient nonlinear iterations, and physical conservation. The PNPF currents are in accord with the experimental I-V (current-voltage) data of the CaVab channel with various voltage. Another simulation method using atomic PF theory adds binding sites in the channel with ions. After calculation, it is concluded that the ion will be stable or not at the binding site. It shows that the theory can describe a "knock-off" mech-anism of calcium selectivity and the transport of ions through the channel.

並列關鍵字

CaVab ； knock-off ； PNPF model ； atomic PF

參考文獻

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