Reevaluating Protein Photoluminescence: Remarkable Visible Luminescence upon Concentration and Insight into the Emission Mechanism. (26th July 2019)

• Record Type: Journal Article
• Authors: Wang, Qian; Dou, Xueyu; Chen, Xiaohong; Zhao, Zihao; Wang, Shuang; Wang, Yunzhong; Sui, Kunyan; Tan, Yeqiang; Gong, Yongyang; Zhang, Yongming; Yuan, Wang Zhang
• Is Part Of: Angewandte Chemie. Volume 131:Number 36(2019)
• Page Start: 12797
• Page End: 12803
• Publication Date: 2019-07-26
• Subjects: Aggregationsinduzierte Emission -- Emission durch Clusterbildung -- Proteine -- Phosphoreszenz -- Lumineszenz; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201906226
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: 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 −1 ), 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. Abstract : Das Licht am Ende des Tunnels : Klar sichtbare Lumineszenz und bei Raumtemperatur anhaltende Phosphoreszenz ( p ‐RTP) werden für konzentrierte und feste Proteine beobachtet, die sich von ihren gut dokumentierten UV‐Emissionen unterscheiden. Dieses Photolumineszenzverhalten kann auf die Ausbildung von Clustern des Peptitrückgrates und anhängender Gruppen mit π‐ und n‐Elektronen zurückgeführt werden, was zu elektronischen Wechselwirkungen durch den Raum und Konformationsversteifung führt.