我們的研究分為兩部分:(I)兩種成分的細胞膜:POPC、POPE;(II)三種成分的細胞膜:POPC、POPE、sterol。利用2H-NMR和DSC,測得POPC/POPE細胞膜的相行為會隨著POPE濃度及溫度而改變。在2H-NMR中,我們以氘取代POPC及POPE sn-1鏈上的氫,來量測POPC及POPE的行為。我們是第一位提出POPE濃度從0到60mol%對溫度的相圖。在相圖上發現一個大範圍的膠態(gel-phase)及液晶態(lc-phase)之兩態共存區。且發現在低於十七度時,POPC及POPE並不是混合得相當均勻,只有在超過十七度時,才有較均勻的混合。 利用POPC及POPE上的氘,2H-NMR測得POPC/POPE細胞膜出現固醇類時(1:1:1 POPC/POPE/ergosterol及1:1:1 POPC/POPE/cholesterol) 的相行為會隨著POPE濃度及溫度而改變。實驗中發現,這兩種固醇,在膠態會降低POPC/POPE (1:1)膜的有序程度,但在液晶態卻能增加POPC/POPE (1:1)膜的有序程度,且麥角酯醇的效應低於膽固醇。在沒有固醇類的情況下,POPC及POPE只能在某些溫度下混合均勻,而混合不均勻的溫度區域,在加入麥角酯醇及膽固醇後,有助於POPC及POPE的混合。此外,對於麥角酯醇幫助POPC/POPE膜均勻混合的能力而言,其作用的溫度範圍明顯小於膽固醇。 We investigate two-component membranes composed of POPE and POPC, and three-component membranes composed of POPE, POPC and sterol. The phase behavior of POPC/POPE membranes was studied as a function of POPE concentration and temperature by 2H-NMR and DSC. For 2H-NMR measurements, POPC and POPE were deuterium labeled alternatively such that the behavior of both POPC and POPE can be observed. We present the first temperature-composition diagram for POPE concentration range from 0 to 60 mol%. Coexistence of the gel and lc phases is observed over a wide temperature and composition range. It is found that POPC and POPE do not mix well in 1:1 POPC/POPE below17℃, but mix well above 17℃. To investigate the properties of POPC/POPE membranes in the presence of sterol, 1:1:1 POPC/POPE/ergosterol and 1:1:1 POPC/POPE/cholesterol were studied as a function of temperature by 2H-NMR, with POPC and POPE deuterium labeled alternatively. We show that the presence of ergosterol (or cholesterol) disorders gel-phase POPC/POPE (1:1) membranes, whereas orders lc-phase POPC /POPE (1:1) membranes. The effect of ergosterol is weaker than cholesterol. Furthermore, the presence of ergosterol (or cholesterol) modulates the mixing properties of POPC/POPE membranes. POPC and POPE mix well in some temperature range, where they are poorly mixed in the absence of sterol. The enhancement of mixing of of POPC/POPE membranes by ergosterol is observed in a temperature range narrower than that by cholesterol.