Institute of Natural Products and Cosmetics, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, Stefanowskiego St. 2/22, 90-537 Lodz, Poland.
Department of Oncobiology and Epigenetics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska St. 141/143, 90-236 Lodz, Poland.
Int J Mol Sci. 2023 Oct 22;24(20):15438. doi: 10.3390/ijms242015438.
The aim of this study was to demonstrate the utility of time-resolved fluorescence spectroscopy in the detection of subtle changes in the local microenvironment of a tryptophan chromophore in a confined and crowded medium of AOT reverse micelles, which mimic biological membranes and cell compartmentalization. For this purpose, fluorescence properties of L-tryptophan and several newly synthesized tryptophan-containing peptides in buffer and in an AOT reverse micelle medium were determined. It was shown that insertion of tryptophan and its short di- and tripeptides inside micelles led to evident changes in both the steady-state emission spectra and in fluorescence decay kinetics. The observed differences in spectral characteristics, such as a blue shift in the emission maxima, changes in the average fluorescence lifetime, and the appearance of environmental-dependent fluorescent species, showed the utility of time-resolved fluorescence spectroscopy as a sensitive tool for detecting subtle conformational modifications in tryptophan and its peptides induced by changes in polarity, viscosity, and specific interactions between chromophores and water molecules/polar groups/ions that occur inside reverse micelles.
本研究旨在展示时间分辨荧光光谱在检测色氨酸发色团在模拟生物膜和细胞区室化的 AOT 反胶束受限和拥挤介质中局部微环境细微变化方面的应用。为此，测定了 L-色氨酸和几种新合成的含色氨酸肽在缓冲液和 AOT 反胶束介质中的荧光性质。结果表明，色氨酸及其短二肽和三肽插入胶束中会导致稳态发射光谱和荧光衰减动力学发生明显变化。观察到的光谱特征差异，如发射峰的蓝移、平均荧光寿命的变化以及环境依赖性荧光物质的出现，表明时间分辨荧光光谱作为一种灵敏工具，可用于检测色氨酸及其肽由于极性、粘度和发色团与水分子/极性基团/离子之间的特定相互作用变化而引起的构象细微变化。
