Intermediates involved in the reduction of SO2: insight into the mechanism of sulfite reductases

Aishik Bhattacharya; Soumya Samanta; Arnab Kumar Nath; Arnab Ghatak; Somdatta Ghosh Dey; Abhishek Dey

doi:10.1039/d4cc02124j

Intermediates involved in the reduction of SO₂: insight into the mechanism of sulfite reductases

Aishik Bhattacharya
, Soumya Samanta
, Arnab Kumar Nath
, Arnab Ghatak
, Somdatta Ghosh Dey
, Abhishek Dey

Research output: Contribution to journal › Article › peer-review

Abstract

Sulfite reductases (SiRs) catalyze the reduction of SO₃²⁻ to H₂S in biosynthetic sulfur assimilation and dissimilation of sulfate. The mechanism of the 6e⁻/6H⁺ reduction of SO₃²⁻ at the siroheme cofactor is debated, and proposed intermediates involved in this 6e⁻ reduction are yet to be spectroscopically characterized. The reaction of SO₂ with a ferrous iron porphyrin is investigated, and two intermediates are trapped and characterized: an initial Fe(iii)-SO₂²⁻ species, which undergoes proton-assisted S-O bond cleavage to form an Fe(iii)-SO species. These species are characterized using a combination of resonance Raman (with ³⁴S-labelled SO₂), EPR and DFT calculations. Results obtained help reconcile the different proposed mechanisms for the SiRs.

Original language	English
Pages (from-to)	7709-7712
Number of pages	4
Journal	Chemical Communications
Volume	60
Issue number	60
DOIs	https://doi.org/10.1039/d4cc02124j
State	Published - 21 Jun 2024
Externally published	Yes

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Catalysis
Ceramics and Composites
General Chemistry
Surfaces, Coatings and Films
Metals and Alloys
Materials Chemistry

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10.1039/d4cc02124j

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title = "Intermediates involved in the reduction of SO2: insight into the mechanism of sulfite reductases",

abstract = "Sulfite reductases (SiRs) catalyze the reduction of SO32− to H2S in biosynthetic sulfur assimilation and dissimilation of sulfate. The mechanism of the 6e−/6H+ reduction of SO32− at the siroheme cofactor is debated, and proposed intermediates involved in this 6e− reduction are yet to be spectroscopically characterized. The reaction of SO2 with a ferrous iron porphyrin is investigated, and two intermediates are trapped and characterized: an initial Fe(iii)-SO22− species, which undergoes proton-assisted S-O bond cleavage to form an Fe(iii)-SO species. These species are characterized using a combination of resonance Raman (with 34S-labelled SO2), EPR and DFT calculations. Results obtained help reconcile the different proposed mechanisms for the SiRs.",

author = "Aishik Bhattacharya and Soumya Samanta and Nath, \{Arnab Kumar\} and Arnab Ghatak and Dey, \{Somdatta Ghosh\} and Abhishek Dey",

note = "Publisher Copyright: {\textcopyright} 2024 The Royal Society of Chemistry.",

year = "2024",

month = jun,

day = "21",

doi = "10.1039/d4cc02124j",

language = "English",

volume = "60",

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publisher = "Royal Society of Chemistry",

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TY - JOUR

T1 - Intermediates involved in the reduction of SO2

T2 - insight into the mechanism of sulfite reductases

AU - Bhattacharya, Aishik

AU - Samanta, Soumya

AU - Nath, Arnab Kumar

AU - Ghatak, Arnab

AU - Dey, Somdatta Ghosh

AU - Dey, Abhishek

PY - 2024/6/21

Y1 - 2024/6/21

N2 - Sulfite reductases (SiRs) catalyze the reduction of SO32− to H2S in biosynthetic sulfur assimilation and dissimilation of sulfate. The mechanism of the 6e−/6H+ reduction of SO32− at the siroheme cofactor is debated, and proposed intermediates involved in this 6e− reduction are yet to be spectroscopically characterized. The reaction of SO2 with a ferrous iron porphyrin is investigated, and two intermediates are trapped and characterized: an initial Fe(iii)-SO22− species, which undergoes proton-assisted S-O bond cleavage to form an Fe(iii)-SO species. These species are characterized using a combination of resonance Raman (with 34S-labelled SO2), EPR and DFT calculations. Results obtained help reconcile the different proposed mechanisms for the SiRs.

AB - Sulfite reductases (SiRs) catalyze the reduction of SO32− to H2S in biosynthetic sulfur assimilation and dissimilation of sulfate. The mechanism of the 6e−/6H+ reduction of SO32− at the siroheme cofactor is debated, and proposed intermediates involved in this 6e− reduction are yet to be spectroscopically characterized. The reaction of SO2 with a ferrous iron porphyrin is investigated, and two intermediates are trapped and characterized: an initial Fe(iii)-SO22− species, which undergoes proton-assisted S-O bond cleavage to form an Fe(iii)-SO species. These species are characterized using a combination of resonance Raman (with 34S-labelled SO2), EPR and DFT calculations. Results obtained help reconcile the different proposed mechanisms for the SiRs.

UR - https://www.scopus.com/pages/publications/85198076269

U2 - 10.1039/d4cc02124j

DO - 10.1039/d4cc02124j

M3 - Article

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AN - SCOPUS:85198076269

SN - 1359-7345

VL - 60

SP - 7709

EP - 7712

JO - Chemical Communications

JF - Chemical Communications

IS - 60

ER -

Intermediates involved in the reduction of SO₂: insight into the mechanism of sulfite reductases

Abstract

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