8IZ3 | pdb_00008iz3

Single excitation and two emissions pH sensor protein(SITE-pHorin)_pH5.5


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.18 Å
  • R-Value Free: 
    0.247 (Depositor), 0.247 (DCC) 
  • R-Value Work: 
    0.170 (Depositor), 0.170 (DCC) 
  • R-Value Observed: 
    0.178 (Depositor) 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


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Literature

A unified intracellular pH landscape with SITE-pHorin: a quantum-entanglement-enhanced pH probe.

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.

(2025) Sci China Life Sci 

  • DOI: https://doi.org/10.1007/s11427-025-2971-5
  • Primary Citation of Related Structures:  
    8IYY, 8IYZ, 8IZ0, 8IZ1, 8IZ2, 8IZ3

  • 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.


  • Organizational Affiliation
    • Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.

Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Green fluorescent protein243Aequorea victoriaMutation(s): 12 
Gene Names: GFP
UniProt
Find proteins for P42212 (Aequorea victoria)
Explore P42212 
Go to UniProtKB:  P42212
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP42212
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
CRO
Query on CRO
A
L-PEPTIDE LINKINGC15 H17 N3 O5THR, TYR, GLY
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.18 Å
  • R-Value Free:  0.247 (Depositor), 0.247 (DCC) 
  • R-Value Work:  0.170 (Depositor), 0.170 (DCC) 
  • R-Value Observed: 0.178 (Depositor) 
Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 50.925α = 90
b = 62.28β = 90
c = 70.477γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-3000data scaling
HKL-3000data reduction
MOLREPphasing

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Natural Science Foundation of China (NSFC)China92054103, 32000855

Revision History  (Full details and data files)

  • Version 1.0: 2024-10-09
    Type: Initial release
  • Version 1.1: 2025-10-22
    Changes: Author supporting evidence, Database references