. 2003 Jan 17;100(3):886–891. doi: 10.1073/pnas.0237311100

Table 1.

Photoreaction of INA and thiols

Exp.	[INA],^* μM	[Thiol],^* μM	Thiol	Medium	Exposure,^† min	INA loss,^‡ %	SH loss,^§ %
1	920	0		n-Heptane	1	86
					2	97
2	0	318	2-ME	n-Heptane	1		7
					2		9
	700	700	2-ME	n-Heptane	1		81
					2		90
3	0	700	2-ME	n-Decane	1		6
					2		10
	700	700	2-ME	n-Decane	1		55
					2		83
4	200	0		Lipo/NP100^¶	2	40
5	0	480	C₁₂SH	Lipo/NP100^¶	2		2
	400	480	C₁₂SH	Lipo/NP100^¶	2		31
	800	480	C₁₂SH	Lipo/NP100^¶	2		43
6	27	1,110	DTT	DM/KP150	0	0

C₁₂SH, t-dodecanethiol; lipo/NP100, 10 mg of asolectin liposomes/ml of 100 mM NaCl/10 mM NaP_i (pH 7.8)/1 mM EDTA/3 mM NaN₃; DM/KP150, 1.1 mM DM/150 mM KCl/10 mM NaP_i (pH 8.0)/1 mM EDTA.

When the medium is a liposome suspension, the concentration is the average over the total volume of the suspension.

^†

XBO light source was used, as described in Materials and Methods.

^‡

The concentration of INA was taken as proportional to A₃₁₀, a local absorbance maximum. In experiment 6, there was no change in the absorbance spectrum of INA during a 20-min exposure to DTT.

^§

Thiol concentration was determined by vigorously mixing 10-μl aliquots of the reaction mixture with 800 μl of 100 μM 5,5′-dithio-bis(2-nitrobenzoate)/100 mM Tris buffer (pH 8.0) for 1 min and determining A₄₁₂ of 700 μl of the bottom phase. [SH] = A₄₁₂/13,600.

^¶

C₁₂SH and INA in liposomes: 0.5 ml of 20 mg asolectin/ml CHCl₃, 0 or 40 μl of 12 mM C₁₂SH/CHCl₃, and 0, 20, 40, or 80 μl of 10 mM INA/CHCl₃ was mixed and dried. The dried lipid was suspended in 1 ml of NP100 and passed 13 times through a 100-nm-pore membrane in a LiposoFast extruder (Avestin, Ottawa).