uu.seUppsala universitets publikasjoner
Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Direct Evidence of a Tryptophan Analogue Radical Formed in a Concerted Electron-Proton Transfer Reaction in Water
Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Fysikalisk kemi.
Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Fysikalisk kemi.
Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Fysikalisk kemi.
2016 (engelsk)Inngår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 138, nr 7, s. 2194-2199Artikkel i tidsskrift (Fagfellevurdert) Published
Resurstyp
Text
Abstract [en]

Proton-coupled electron transfer (PCET) is a fundamental reaction step of many chemical and biological processes. Well-defined biomimetic systems are promising tools for investigating the PCET mechanisms relevant to natural proteins. Of particular interest is the possibility to distinguish between stepwise and concerted transfer of the electron and proton, and how PCET is controlled by a proton acceptor such as water. Thus, many tyrosine and phenolic derivatives have been shown to undergo either stepwise or concerted PCET, where the latter process is defined by simultaneous tunneling of the electron and proton from the same transition state. For tryptophan instead, it is theoretically predicted that a concerted pathway can never compete with the stepwise electron-first mechanism (ETPT) when neat water is the primary proton acceptor. The argument is based on the radical pK(a)(similar to 4.5) that is much higher than that for water (pK(a)(H3O+) = 0), which thermodynamically disfavors a concerted proton transfer to H2O. This is in contrast to the very acidic radical cation of tyrosine (pK(a) similar to -2). However, in this study we show, by direct time-resolved absorption spectroscopy on two [Ru(bpy)(3)](2+) tryptophan (bpy = 2,2'-bipyridine) analogue complexes, that also tryptophan oxidation with water as a proton acceptor can occur via a concerted pathway, provided that the oxidant has weak enough driving force. This rivals the theoretical predictions and suggests that our current understanding of PCET reactions in water is incomplete.

sted, utgiver, år, opplag, sider
2016. Vol. 138, nr 7, s. 2194-2199
HSV kategori
Identifikatorer
URN: urn:nbn:se:uu:diva-282314DOI: 10.1021/jacs.5b08294ISI: 000371103900031PubMedID: 26871741OAI: oai:DiVA.org:uu-282314DiVA, id: diva2:916852
Forskningsfinansiär
Swedish Research CouncilSwedish Energy AgencyKnut and Alice Wallenberg FoundationTilgjengelig fra: 2016-04-05 Laget: 2016-04-05 Sist oppdatert: 2017-11-30

Open Access i DiVA

Fulltekst mangler i DiVA

Andre lenker

Forlagets fulltekstPubMed

Personposter BETA

Dongare, PrateekHammarström, Leif

Søk i DiVA

Av forfatter/redaktør
Dongare, PrateekHammarström, Leif
Av organisasjonen
I samme tidsskrift
Journal of the American Chemical Society

Søk utenfor DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetric

doi
pubmed
urn-nbn
Totalt: 633 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf