Title
Self-Assembled Nanostructures Based on Activatable Red Fluorescent Dye for Site-Specific Protein Probing and Conformational Transition Detection
Author
Yang Yu, Yanyan Huang, Fang Hu, Yulong Ji, Guanxin Zhang, Deqing Zhang, Rui Zhao
Year
2016
Journal
Analytical Chemistry
Abstract
Smart and versatile nanostructures have demonstrated their effectiveness for biomolecule analysis and show great potential in digging insights into the structural/functional relationships. Herein, a nanoscale molecular self-assembly was constructed for probing the site-specific recognition and conformational changes of human serum albumin (HSA) with tunable size and emission. A tetraphenylethylene derivative TPE-red-COOH was used as the building block for tailoring fluorescence-silent nanoparticles. The highly specific and sensitive response to HSA was witnessed by the fast turn-on of the red fluorescence and simultaneous disassembly of the nanostructures, whereas various endogenous biomolecules cannot induce such response. The mechanism investigation indicates that the combination of multiple non-covalent interactions is the driving force for disassembling and trapping TPE-red-COOH into HSA. The resultant restriction of intramolecular rotation of TPE-red-COOH in the hydrophobic cavity of HSA induces the significant red emission. By using the fluorescence activatable nanosensor as the structural indicator, the step-wise conformational transitions of HSA during denaturing and the partial refolding of subdomain IIA of HSA was facilely visualized. Benefiting from its activatable signaling, sensitivity and simplicity, such molecular assembly provides a kind of soft nanomaterial for site-specific biomolecule probing and conformational transition detection concerning their structure, function and biomedical characteristics.
Instrument
J-815
Keywords
Circular dichroism, Secondary structure, Nanostructures, Protein folding, Protein denaturation, Materials