MECHANISM OF TRYPTOPHAN FLUORESCENCE QUENCHING

我们研究了时间分辨和稳态荧光 N-乙酰基-L-甘露酰胺的淬灭。 （NATA）由丙烯酰胺和 碘化物，在丙二醇中的粘度范围内。 的 丙烯酰胺和碘化物对NATA的淬灭导致了 强度衰减随猝灭剂浓度的增加而增加。 我们将NATA的复杂衰减归因于 扩散和荧光团-猝灭剂相互作用的性质。 考虑频域和稳态数据 证明淬火速率指数依赖于 荧光团猝灭距离，表明模型的有效性 其包括猝灭常数，猝灭常数指数地依赖于 距离 这样的数据对距离的依赖淬火是 对理解天然蛋白质的淬灭很重要。

We examined the time-resolved and steady-state fluorescence quenching of N-acetyl-L-tryptophanamide. (NATA) by acrylamide and iodide, over a range of viscosities in propylene glycol. The quenching of NATA by acrylamide and iodide results in heterogeneity of the intensity decay which increases with the quencher concentration. We attribute the complex decay of NATA to transient effects in diffusion and the nature of the fluorophore-quencher interaction. Consideration of both the frequency-domain and steady-state data demonstrate that the quenching rate depends exponentially on the fluorophore-quencher distance, indicating the validity of a model which include a quenching constant which depend exponentially on distance. Such data on the distance dependence of quenching is important for understanding quenching of native proteins.