Beitrag zur Aufklärung des molekularen Mechanismus von Ionenkanälen mittels neuartiger FTIR-spektroskopischer Methoden
Biologische und Biomimetische Chemie
Zusammenfassung der Projektergebnisse
This Sino-German collaborative research project aimed at developing bio/nano-material hybrids for novel optogenetic experiments. The primary objective was to overcome the challenge of delivering activating light to deeply embedded target proteins. To address this challenge, we utilized near-infrared (NIR) light, known for its ability to penetrate deeper into tissues. Specifically, we employed lanthanide-doped upconversion nanoparticles (UCNPs) to convert lowenergy NIR radiation into high-energy visible light, which in turn can activate microbial rhodopsins, the primary biological photoreceptors. Initially, the research project focused on investigating the proof of concept. By employing FTIR spectroscopy, the conformational changes of NpSRII upon NIR light excitation in the presence of UCNPs were confirmed under dry conditions. The findings from this phase of the study were summarized and subsequently published. Subsequent experiments were conducted in an aqueous environment to replicate conditions similar to those in a biological setting. Unexpectedly, the results revealed a suppression of the photoactivity of NpSRII when mixed with UCNPs in an aqueous solution. The researchers hypothesized that this inactivation might be attributed to energy back-flow from NpSRII to UCNPs. To test this hypothesis, a control experiment was performed by coating the UCNPs' surface with a lipid bilayer to prevent direct contact with NpSRII. The results partially supported the hypothesis, suggesting the necessity of precise control over the gap distance between NpSRII and UCNPs to optimize photoexcitation without quenching. We also found that the presence of UCNPs modulates the kinetics of the photocycle of NpSRII. Consequently, time-resolved FTIR measurements were identified as essential for a better understanding of the system in future investigations. In conclusion, this research project demonstrates the activation of microbial rhodopsins through NIR illumination using UCNPs. Furthermore, it underscores the importance of further investigations to optimize the bio/nano-material hybrid system for optogenetic applications.
Projektbezogene Publikationen (Auswahl)
-
Near-Infrared Activation of Sensory Rhodopsin II Mediated by NIR-to-Blue Upconversion Nanoparticles. Frontiers in Molecular Biosciences, 8.
Yaguchi, Momo; Jia, Xiaodan; Schlesinger, Ramona; Jiang, Xiue; Ataka, Kenichi & Heberle, Joachim
