State Key Laboratory of Bio-fibers and Eco-textiles, Collaborative Innovation Center for Marine Biobased Fibers and Ecological Textile Technology, School of Materials Science and Engineering, Qingdao University, Qingdao, 266071, China.
School of Chemistry and Chemical Engineering, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Electrochemical Energy Devices Research Center, Shanghai Jiao Tong University, Shanghai, 200240, China.
Angew Chem Int Ed Engl. 2019 Sep 2;58(36):12667-12673. doi: 10.1002/anie.201906226. Epub 2019 Jul 26.
It is a textbook knowledge that protein photoluminescence stems from the three aromatic amino acid residues of tryptophan(Trp), tyrosine (Tyr), and phenylalanine (Phe), with predominant contributions from Trp. Recently, inspired by the intrinsic emission of nonaromatic amino acids and poly(amino acids) in concentrated solutions and solids, we revisited protein light emission using bovine serum albumin (BSA) as a model. BSA is virtually nonemissive in dilute solutions (≤0.1 mg mL ), but highly luminescent upon concentration or aggregation, showing unique concentration-enhanced emission and aggregation-induced emission (AIE) characteristics. Notably, apart from well-documented UV luminescence, bright blue emission is clearly observed. Furthermore, persistent room-temperature phosphorescence (p-RTP) is achieved even in the amorphous solids under ambient conditions. This visible emission can be rationalized by the clustering-triggered emission (CTE) mechanism. These findings not only provide an in-depth understanding of the emissive properties of proteins, but also hold strong implications for further elucidating the basis of tissue autofluorescence.
这是教科书上的知识，蛋白质的光致发光源于色氨酸（Trp）、酪氨酸（Tyr）和苯丙氨酸（Phe）这三种芳香族氨基酸残基，其中以 Trp 贡献为主。最近，受非芳香族氨基酸和聚（氨基酸）在浓溶液和固体中固有发射的启发，我们使用牛血清白蛋白（BSA）作为模型重新研究了蛋白质的光致发光。BSA 在稀溶液（≤0.1mg/mL）中几乎不发光，但在浓缩或聚集时会发出很强的光，表现出独特的浓度增强发射和聚集诱导发射（AIE）特性。值得注意的是，除了有充分文献记载的紫外发光外，还明显观察到明亮的蓝色发射。此外，即使在环境条件下的无定形固体中，也能实现持续的室温磷光（p-RTP）。这种可见发射可以用聚集触发发射（CTE）机制来解释。这些发现不仅深入了解了蛋白质的发光特性，而且对进一步阐明组织自发荧光的基础具有重要意义。
