8IZ2

Single excitation and two emissions pH sensor protein (SITE-pHorin)_C203E_pH8.0

8IZ2 の概要

• エントリーDOI: 10.2210/pdb8iz2/pdb
• 分子名称: Green fluorescent protein (2 entities in total)
• 機能のキーワード: monomer, fluorescent protein
• 由来する生物種: Aequorea victoria (Water jellyfish, Mesonema victoria)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 27703.18

構造登録者

Kang, J.S.,Li, S.A. (登録日: 2023-04-06, 公開日: 2024-10-09, 最終更新日: 2026-03-18)

主引用文献

Li, S.A.,Meng, X.Y.,Zhang, S.,Zhang, Y.J.,Yang, R.Z.,Wang, D.D.,Yang, Y.,Liu, P.P.,Kang, J.S.
A unified intracellular pH landscape with SITE-pHorin: a quantum-entanglement-enhanced pH probe.
Sci China Life Sci, 2025

PubMed Abstract: An accurate map of intracellular organelle pH is crucial for comprehending cellular metabolism and organellar functions. However, a unified intracellular pH spectrum using a single probe is still lacking. Here, we developed a novel quantum entanglement-enhanced pH- sensitive probe called SITE-pHorin (single excitation and two emissions pH sensor protein), which features a wide pH-sensitive range and ratiometric quantitative measurement capabilities. We subsequently measured the pH of various organelles and their subcompartments, including mitochondrial subspaces, Golgi stacks, endoplasmic reticulum (ER), lysosomes, peroxisomes, and endosomes in COS-7 cells. For the long-standing debate on the pH of the mitochondrial compartments, we measured the pH of the mitochondrial cristae (mito-cristae) as 6.60±0.40, the pH of the mitochondrial intermembrane space (mito-IMS) as 6.95±0.30, and the pH of the two populations of the mitochondrial matrix (mito-matrix) at approximately 7.20±0.27 and 7.50±0.16, respectively. Notably, the pH of the lysosome exhibited a single, narrow Gaussian distribution centered at 4.79±0.17, which is consistent with an optimal lysosomal acidic pH between 4.5 and 5.0. Furthermore, quantum chemistry computations revealed that both the deprotonation of the residue Y182 and the discrete curvature of the deformed benzene ring in the chromophore are necessary for the quantum entanglement mechanism of SITE-pHorin. Intriguingly, our findings reveal an accurate pH gradient (0.6-0.9 pH units) between the mitochondrial cristae and the mitochondrial matrix, suggesting that prior knowledge about ΔpH (0.4-0.6) and the mitochondrial proton motive force (pmf) is underestimated.

PubMed: 40956361
DOI: 10.1007/s11427-025-2971-5

実験手法

X-RAY DIFFRACTION (1.572 Å)