Rodembusch Fabiano Severo, Leusin Fernando Paulus, da Costa Medina Luis Fernando, Brandelli Adriano, Stefani Valter
Universidade Federal do Rio Grande do Sul - Instituto de Quimica, Laboratorio de Novos Materiais Organicos, Av. Bento Goncalves, 9500. CP 15003, CEP 91501-970, Porto Alegre-RS, Brazil.
Photochem Photobiol Sci. 2005 Mar;4(3):254-9. doi: 10.1039/b409233c. Epub 2005 Jan 20.
Three new benzazole isothiocyanate fluorescent dyes, 2-(4'-isothiocyanate-2'-hydroxyphenyl)benzoxazole, 2-(4'-isothiocyanate-2'-hydroxyphenyl)benzothiazole and 2-(4'-isothiocyanate-2'-hydroxyphenyl)benzimidazole were synthesised, purified until optical purity grade and characterised by spectroscopic techniques. UV/VIS and steady-state fluorescence were also applied to characterise the photophysical behaviour of the dyes. These dyes exhibit an intense fluorescence emission with a large Stokes shift, inherent to the class of benzazoles which relax by the excited state intramolecular proton transfer (ESIPT) mechanism. The dyes were studied for labeling bovine serum albumin (BSA), resulting conjugates BSA-dye with a remarkable photostability under UV/VIS radiation in relation to classical protein labels. The resulting conjugates presented fluorescence in the blue-green region. Direct fluorescence detection of protein-labeled with those dyes after polyacrylamide gel electrophoresis indicates their potential use as fluorescent probes for proteins.
合成了三种新型苯并唑异硫氰酸酯荧光染料，即2-(4'-异硫氰酸酯-2'-羟基苯基)苯并恶唑、2-(4'-异硫氰酸酯-2'-羟基苯基)苯并噻唑和2-(4'-异硫氰酸酯-2'-羟基苯基)苯并咪唑，将其纯化至光学纯级别，并通过光谱技术进行表征。紫外可见光谱和稳态荧光也用于表征这些染料的光物理行为。这些染料表现出强烈的荧光发射，具有较大的斯托克斯位移，这是苯并唑类通过激发态分子内质子转移(ESIPT)机制弛豫所固有的。研究了这些染料对牛血清白蛋白(BSA)的标记，相对于传统蛋白质标记物，所得的共轭物BSA-染料在紫外可见辐射下具有显著的光稳定性。所得共轭物在蓝绿色区域呈现荧光。聚丙烯酰胺凝胶电泳后用这些染料标记蛋白质的直接荧光检测表明它们作为蛋白质荧光探针的潜在用途。
