色氨酸类似物标记法研究DsbA蛋白的结构环境

Study of the Structural Environment of DsbA Protein by Labeling of Tryptophan Analogs

用生物标记的方法将色氨酸类似物标记在DsbA蛋白中的色氨酸位置 ,分析标记蛋白质的谱学性质、色氨酸结构环境和潜在应用前景 .5 OH Trp标记的DsbA蛋白具有 315nm激发的荧光发射光谱 ;1 9F NMR能分辨 5 F Trp标记的DsbA蛋白的两个F Trp残基 (Trp76和Trp12 6 ) ,Trp76化学位移变化反映二硫键交换引起的结构转化 .进一步将利用标记蛋白的独特荧光和1 9F NMR性质 ,研究DsbA蛋白的氧化还原及与底物蛋白的结合作用 .

Tryptophan analogs were biosynthetically incorporated into the tryptophan sites of DsbA protein to investigate the spectroscopic characteristics, local environments of tryptophans. This technique by using tryptophan-analog labeling may be of potential application to studying structure-function relationships and protein-protein interactions. 5-hydroxytryptophan labeled DsbA protein presents a fluorescence excitation wavelength at 315 rim and an emission near 340 rim. The chemical shifts of Trp76 and Trp126 in 5-fluorotrytophan labeled DsbA were identified in F-19-NMR spectra, and change of the chemical shift of Trp76. p can reflect the conformational change of DsbA protein during redox reaction. The future work is to use specific fluorescence and F-19-NMR of labeled DsbA protein to study its redox properties and interaction with substrates.