TABLE 2.

Mole-fraction partition coefficients of nystatin, K_p, for different phospholipid vesicles and temperatures

Model system of membranes	Phospholipid	T (°C)	Buffer	Kp (×104)
SUV	DPPC	21	Tris	6.5 ± 0.8*
			HEPES	5.8 ± 0.7
		45	Tris	1.4 ± 0.3
			HEPES	1.6 ± 0.3
LUV	DPPC	21	HEPES	1.1 ± 0.3
		45	HEPES	0.9 ± 0.1
	POPC	21	HEPES	1.4 ± 0.2

Partition coefficients were obtained from steady-state fluorescence intensity data as described in Materials and Methods. It was considered that only 60% and 50% of the total lipid of SUV and LUV could interact with the antibiotic, respectively.

^*Coutinho and Prieto (1995).