title: Self-assembly-induced far-red/near-infrared fluorescence light-up for detecting and visualizing specific protein-Peptide interactions.
abstract: Understanding specific protein-peptide interactions could offer a deep insight into the development of therapeutics for many human diseases. In this work, we designed and synthesized a far-red/near-infrared (FR/NIR) fluorescence light-up probe (DBT-2EEGWRESAI) by simply integrating two tax-interacting protein-1 (TIP-1)-specific peptide ligands (EEGWRESAI) with one 4,7-di(thiophen-2-yl)-2,1,3-benzothiadiazole (DBT) unit. We first demonstrated that DBT is an environment-sensitive fluorophore with FR/NIR fluorescence due to its strong charge transfer character in the excited state. Thanks to the environmental sensitivity of DBT, the probe DBT-2EEGWRESAI is very weakly fluorescent in aqueous solution but lights up its fluorescence when the probe specifically binds to TIP-1 protein or polyprotein (ULD-TIP-1 tetramer). It is found that the DBT-2EEGWRESAI/TIP-1 protein and the DBT-2EEGWRESAI/ULD-TIP-1 tetramer could self-assemble into spherical nanocomplexes and a nanofiber network, respectively, which lead to probe fluorescence turn-on through providing DBT with a hydrophobic microenvironment. By virtue of the self-assembly-induced FR/NIR fluorescence turn-on, DBT-2EEGWRESAI can detect and visualize specific protein/polyprotein-peptide interactions in both solution and live bacteria in a high contrast and selective manner.
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Sciences, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University , Tianjin 300071, People's Republic of China.
authors.forename: Huaimin
authors.initials: H
authors.lastname: Wang
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Aitian
authors.initials: A
authors.lastname: Han
authors.forename: Nannan
authors.initials: N
authors.lastname: Xiao
authors.forename: Zhaosheng
authors.initials: Z
authors.lastname: Xue
authors.forename: Gang
authors.initials: G
authors.lastname: Wang
authors.forename: Jiafu
authors.initials: J
authors.lastname: Long
authors.forename: Deling
authors.initials: D
authors.lastname: Kong
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.forename: Zhimou
authors.initials: Z
authors.lastname: Yang
authors.forename: Dan
authors.initials: D
authors.lastname: Ding
mesh_terms: D005453:Fluorescence; D009682:Magnetic Resonance Spectroscopy; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D010455:Peptides / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*
chemical_list: D010455:Peptides; D011506:Proteins