Sanyal G, Kim E, Thompson F M, Brady E K
Department of Chemistry, Hamilton College, Clinton, New York 13323.
Biochem Biophys Res Commun. 1989 Dec 15;165(2):772-81. doi: 10.1016/s0006-291x(89)80033-6.
The quenching of fluorescence of 5-methoxyindole, N-acetyl-L-tryptophanamide and two single tryptophan containing peptides, melittin and mastoparan X, by oxidized dithiothreitol was studied. The slopes of the Stern-Volmer plots for steady-state fluorescence quenching were 133 M-1, 71.2 M-1, 75.5 M-1 and 35.0 M-1 at 21 degrees C and pH 7.0 for 5-methyoxyindole, N-acetyl-L-tryptophanamide, melittin and mastoparan X respectively. Fluorescence lifetimes of indole or tryptophan in these compounds, as determined by multifrequency phase fluorometry, were decreased by 15% or less at concentrations that produced 50% or more quenching of steady-state fluorescence. Thus, quenching of fluorescence by oxidized dithiothreitol for these derivatives of indole appears to be largely static in nature, suggesting a ground-state interaction.
研究了氧化型二硫苏糖醇对5-甲氧基吲哚、N-乙酰-L-色氨酸酰胺以及两种含单个色氨酸的肽（蜂毒肽和mastoparan X）荧光的猝灭作用。在21℃和pH 7.0条件下，5-甲氧基吲哚、N-乙酰-L-色氨酸酰胺、蜂毒肽和mastoparan X的稳态荧光猝灭的Stern-Volmer图斜率分别为133 M-1、71.2 M-1、75.5 M-1和35.0 M-1。通过多频相荧光法测定，在导致稳态荧光猝灭50%或更多的浓度下，这些化合物中吲哚或色氨酸的荧光寿命降低了15%或更少。因此，氧化型二硫苏糖醇对这些吲哚衍生物的荧光猝灭在本质上似乎主要是静态的，这表明存在基态相互作用。
