Organelle-Specific pH Quantification Using a Protein-Based Quantum Sensor
- 1Institute for Quantum Life Science (iQLS), National Institutes for Quantum Science and Technology (QST); Center of Quantum Life Science for Structural Therapeut
Abstract
Quantum sensing enables measurements of physicochemical changes within living cells at the organelle level. Conventional nanoparticle-based sensors, however, face limitations in subcellular targeting, intracellular tracking, and following dynamic biological processes across distinct intracellular environments. Here, we investigate MagLOV2, a genetically encoded quantum sensor, by examining its organelle-specific localization, magnetic field effects (MFEs) during mitophagy, and pH dependent response kinetics. MagLOV2 retained magnetic responsiveness in the cytoplasm, nucleus, and mitochondria, with fluorescence contrasts of 17.1%, 12.3%, and 28.0%, respectively. Optimization of mitochondrial targeting increased fluorescence 2.7 fold. During CCCP induced mitophagy, lysosomal colocalization of MagLOV2 increased from 20.75% to 89.73%, accompanied by slower MFE responses in acidic compartments. Purified MagLOV2 showed response times ranging from 8.27 s at pH 4.5 to 1.56 s at pH 9.5. Structural, spectral, and kinetic analyses suggested that protonation dependent flavin photochemistry and the surrounding protein environment contribute to this behavior. These measurements demonstrate that genetically targeted MagLOV2 can follow organelle transport and report local acidification through changes in magnetic-response kinetics.
Related
- A Solution-Gated Graphene Transistor Sensor for the Detection and Quantification of Guanine Quadruplexes.
- Organelle-specific mechanisms and AI-guided stratification in gut-renal-vascular axis modulation
- Accurate quantification of protein concentrations and state populations by 2D 1H-N Q-BEST NMR
- Simultaneous quantification and natural abundance δ15N analysis of protein-bound amino acids in human lung tissue by GC-C-IRMS
- Design and Validation of New Primers for Specific and Sensitive Real-time PCR Detection and Quantification of Seven Botulinum Encoding Genes (Serotype A-G) of Clostridium botulinum
BibTeX
@misc{seki2026organellespecific,
title = {{Organelle-Specific pH Quantification Using a Protein-Based Quantum Sensor}},
author = {M. Seki and S. Aizawa and Y. Shigeno and N. Maita and S. Chen and M. Kato and S. Ogasawara and T. Murata and L. M. Antill and H. Ishiwata},
howpublished = {bioRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.19.760020},
url = {https://www.biorxiv.org/content/10.64898/2026.10.19.760020v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Organelle-Specific pH Quantification Using a Protein-Based Quantum Sensor
AU - M. Seki
AU - S. Aizawa
AU - Y. Shigeno
AU - N. Maita
AU - S. Chen
AU - M. Kato
AU - S. Ogasawara
AU - T. Murata
AU - L. M. Antill
AU - H. Ishiwata
PY - 2026
DA - 2026/10/19
PB - bioRxiv
DO - 10.64898/2026.10.19.760020
UR - https://www.biorxiv.org/content/10.64898/2026.10.19.760020v1
AB - Quantum sensing enables measurements of physicochemical changes within living cells at the organelle level. Conventional nanoparticle-based sensors, however, face limitations in subcellular targeting, intracellular tracking, and following dynamic biological processes across distinct intracellular environments. Here, we investigate MagLOV2, a genetically encoded quantum sensor, by examining its organelle-specific localization, magnetic field effects (MFEs) during mitophagy, and pH dependent response kinetics. MagLOV2 retained magnetic responsiveness in the cytoplasm, nucleus, and mitochondria, with fluorescence contrasts of 17.1%, 12.3%, and 28.0%, respectively. Optimization of mitochondrial targeting increased fluorescence 2.7 fold. During CCCP induced mitophagy, lysosomal colocalization of MagLOV2 increased from 20.75% to 89.73%, accompanied by slower MFE responses in acidic compartments. Purified MagLOV2 showed response times ranging from 8.27 s at pH 4.5 to 1.56 s at pH 9.5. Structural, spectral, and kinetic analyses suggested that protonation dependent flavin photochemistry and the surrounding protein environment contribute to this behavior. These measurements demonstrate that genetically targeted MagLOV2 can follow organelle transport and report local acidification through changes in magnetic-response kinetics.
ER -