# Decoding in-cell respiratory enzyme dynamics by label-free in situ electrochemistry

https://mdr.nims.go.jp/datasets/f76cc184-3885-4684-a401-d33e045c2d23

## Files

- [tokunou-et-al PNAS2025-decoding-in-cell-respiratory-enzyme-dynamics-by-label-free-in-situ-electrochemistry.pdf](https://mdr.nims.go.jp/filesets/16472629-c277-46a8-8d93-9e13980be009/download) ([Detail](https://mdr.nims.go.jp/filesets/16472629-c277-46a8-8d93-9e13980be009.md))
- [pnas.2418926122.sapp.pdf](https://mdr.nims.go.jp/filesets/0afa79a8-c7eb-4fb7-b72f-e65b386542a7/download) ([Detail](https://mdr.nims.go.jp/filesets/0afa79a8-c7eb-4fb7-b72f-e65b386542a7.md))

## Id

f76cc184-3885-4684-a401-d33e045c2d23

## Local identifier



## Visibility

open_to_public

## State

published

## Created at

2025-12-12T03:17:28.560943Z

## Updated at

2025-12-24T07:46:17.774687Z

## Published at

2025-12-24T23:19:49.620820Z

## Doi



## First published url

https://doi.org/10.1073/pnas.2418926122

## Date published

2025-03-25

## Recorded date published

2025-3-25

## Resource type

journal_article

## Manuscript type

vor

## Collection



## Title

- title: Decoding in-cell respiratory enzyme dynamics by label-free in situ electrochemistry
  title_type: original
  lang: en

## Description

- description: 'Deciphering metabolic enzyme catalysis in living cells remains a formidable
    challenge due to the limitations of in vivo assays, which focus on enzymes isolated
    from respiration. This study introduces an innovative whole-cell electrochemical
    assay to reveal the Michaelis–Menten landscape of respiratory enzymes amid complex
    molecular interactions. We controlled the microbial current generation’s rate-limiting
    step, extracting in vivo kinetic parameters (Km, Ki, and kcat) for the periplasmic
    nitrite (NrfA) and fumarate (FccA) reductases. Notably, while NrfA kinetics mirrored
    those of its purified form, FccA exhibited unique kinetic behavior. Further exploration
    using a mutant strain lacking CymA, a periplasmic hub protein, revealed its crucial
    role in modulating FccA’s kinetics, challenging the prevailing view that molecular
    crowding is the main cause of discrepancies between in vivo and in vitro enzyme
    kinetics. '
  description_type: abstract
  lang: und

## Creator

- name: Yoshihide Tokunou
  role: author
  orcid: https://orcid.org/0000-0002-0983-6176
- name: Tomohiko Yamazaki
  role: author
  orcid: https://orcid.org/0000-0003-2136-8042
- name: Takashi Fujikawa
  role: author
  orcid: https://orcid.org/0000-0001-7734-546X
- name: Akihiro Okamoto
  role: author
  orcid: https://orcid.org/0000-0002-8102-4316

## Contact agent



## Publisher

organization: Proceedings of the National Academy of Sciences

## Managing organization



## Keyword

- subject: Michaelis–Menten equation
  schema: not_defined
- subject: interprotein interaction
  schema: not_defined
- subject: enzymatic activity
  schema: not_defined

## Rights

- identifier: https://creativecommons.org/licenses/by-nc-nd/4.0/

## Other identifier(s)



## Data origin



## Embargo



## Journal

- title: Proceedings of the National Academy of Sciences
  issn: '00278424'
  volume: '122'
  issue: '12'
  article_number: e2418926122

## Conference



## Related item



## Funding

- identifier: JPMJAX211C
  funder_name: MEXT | JST | ACT-X
- identifier: 20K15428
  funder_name: MEXT | Japan Society for the Promotion of Science
- identifier: JPMJGX23B2
  funder_name: MEXT | Japan Science and Technology Agency
- identifier: JPMXP1223NM5212
  funder_name: MEXT ARIM
- identifier: None
  funder_name: University of Tsukuba
- identifier: JST FOREST
  funder_name: MEXT | JST | Fusion Oriented REsearch for disruptive Science and Technology
- identifier: 22KK0242
  funder_name: MEXT | Japan Society for the Promotion of Science
- identifier: 23K23532
  funder_name: MEXT | Japan Society for the Promotion of Science

## Instrument



## Instrument operator



## Instrument managing organization



## Measurement method



## Specimen



## Chemical composition



## Structure for specimen



## Structural feature for specimen



## Specific property for specimen



## Process for specimen treatment



## Computational method



## Energy level/transition state



## Software



## Custom property



## Fileset

- id: 16472629-c277-46a8-8d93-9e13980be009
  filename: tokunou-et-al PNAS2025-decoding-in-cell-respiratory-enzyme-dynamics-by-label-free-in-situ-electrochemistry.pdf
  content_type: application/pdf
  size: 4397275
  md5: 3e678e3f50c47f9f51cac166540a1f33
- id: 0afa79a8-c7eb-4fb7-b72f-e65b386542a7
  filename: pnas.2418926122.sapp.pdf
  content_type: application/pdf
  size: 2037060
  md5: c51ba78dd58ad9467f12110e50eba99b

## Thumbnail

fileset_id: 16472629-c277-46a8-8d93-9e13980be009
filename: tokunou-et-al PNAS2025-decoding-in-cell-respiratory-enzyme-dynamics-by-label-free-in-situ-electrochemistry.pdf