Evidence map›Paper›PMID 41950924›Full record

ArticleCell chemical biology2026

Directed evolution of APOX for proximity labeling using phenols with high redox potentials.

Sifei Fang, Leslie D Acevedo, Alexander J Solivais, Xu Zhou, Swapnali S Patil, Elliot S Delfosse, Hang Yin, Zachary B Ziolkowski, Brian L Frey, Edwin R Chapman and 2 more

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Cell chemical biology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

4 citing papers in PubMed.

  1. Review
  2. AbioRxiv : the preprint server for biology · 2026
    Article
  3. Article
  4. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

12 authors.

Sifei FangDepartment of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
Leslie D AcevedoDepartment of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
Alexander J SolivaisDepartment of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
Xu ZhouDepartment of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
Swapnali S PatilDepartment of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA; Howard Hughes Medical Institute, Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA.
Elliot S DelfosseDepartment of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
Hang YinDepartment of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
Zachary B ZiolkowskiDepartment of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
Brian L FreyDepartment of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
Edwin R ChapmanDepartment of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA; Howard Hughes Medical Institute, Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA.
Lloyd M SmithDepartment of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
Jeffrey D MartellDepartment of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA; Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53706, USA. Electronic address: jdmartell@wisc.edu.

Funding

Synaptotagmin C2B Domain as a Ca2+ Sensing ModuleR01MH061876 · NIMH · UNIVERSITY OF WISCONSIN-MADISON · PI Edwin R Chapman · 2002 to 2026
$7.7M
Revealing Proteoforms: The Primary Effectors of Biological FunctionR35GM126914 · NIGMS · UNIVERSITY OF WISCONSIN-MADISON · PI Lloyd M Smith · 2018 to 2026
$6.2M
Hybrid Biological-Abiotic Proximity Labeling Catalysts for Enhancing Spatially-Resolved ProteomicsR01GM150698 · NIGMS · UNIVERSITY OF WISCONSIN-MADISON · PI Jeffrey Daniel Martell · 2023 to 2026
$1.5M
Fusion pore structure and dynamicsR35NS136306 · NINDS · UNIVERSITY OF WISCONSIN-MADISON · PI Edwin R Chapman · 2025 to 2026
$1.3M
Howard Hughes Medical InstituteNIGMS NIH HHS R01 GM150698NIGMS NIH HHS R35 GM126914NIMH NIH HHS R01 MH061876NINDS NIH HHS R35 NS136306
6 · The paper itself

Abstract

Proximity labeling (PL) can identify endogenous proteins in specific subcellular regions. APEX2 (enhanced ascorbate peroxidase 2) enables PL with high temporal resolution by oxidizing biotin phenol (BP) into a radical that promiscuously tags nearby proteins, followed by the isolation and identification of the tagged biomolecules. However, the BP radical has a relatively large diffusion radius, limiting spatial resolution. Replacing the phenol in BP with nitrophenol (NP) could shorten the labeling radius by shortening the radical lifetime, but existing PL heme peroxidases cannot efficiently oxidize substrates with high redox potentials. We report the ultrahigh-throughput directed evolution of APOX (APEX with high redOX potential), a quadruple mutant of APEX2 with a higher reduction potential. Using APOX with a membrane-permeable alkyne-NP probe, we demonstrate PL in living mammalian cells, including proteomic mapping with excellent subcellular compartment specificity.

Indexed as

Ascorbate PeroxidasesDirected Molecular EvolutionPhenolsAnimalsBiotinHumansOxidation-ReductionStaining and LabelingAscorbate PeroxidasesBiotinPhenolsdirected evolutionproximity labeling

Identifiers

PMID41950924
PMCPMC13218423

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.