Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • 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
Hydrolysis of the E2P Phosphoenzyme of the Ca2+-ATPase: A Theoretical Study
Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
2013 (engelsk)Inngår i: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 117, nr 31, s. 9224-9232Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Dephosphorylation of the E2P phosphoenzyme intermediate of the sarcoplasmic reticulum Ca2+-ATPase was studied using density functional theory. The hydrolysis reaction proceeds via a nucleophilic attack on the phosphorylated residue Asp351 by a water molecule, which is positioned by the nearby residue Glu183 acting as a base. The activation barrier was calculated to be 14.3 kcal/mol, which agrees well with values of 15-17 kcal/mol derived from experimentally observed rates. The optimized structure of the transition state reveals considerable bond breakage between phosphorus and the Asp351 oxygen (distance 2.19 angstrom) and little bond formation to the attacking water oxygen (distance 2.26 angstrom). Upon formation of the singly protonated phosphate product, Glu183 becomes protonated. The bridging aspartyl phosphate oxygen approaches Lys684 progressively when proceeding from the reactant state (distance 1.94 angstrom) via the transition state (1.78 angstrom) to the product state (1.58 angstrom). This stabilizes the negative charge that develops on the leaving group. The reaction was calculated to be slightly endergonic (+0.9 kcal/mol) and therefore reversible, in line with experimental findings. It is catalyzed by a preorganized active site with little movement of the nonreacting groups except for a rotation of Thr625 toward the phosphate group.

sted, utgiver, år, opplag, sider
2013. Vol. 117, nr 31, s. 9224-9232
HSV kategori
Identifikatorer
URN: urn:nbn:se:su:diva-94189DOI: 10.1021/jp4049814ISI: 000323082200010OAI: oai:DiVA.org:su-94189DiVA, id: diva2:652553
Forskningsfinansiär
Swedish Research Council
Merknad

AuthorCount:3;

Tilgjengelig fra: 2013-10-01 Laget: 2013-09-30 Sist oppdatert: 2017-12-06bibliografisk kontrollert

Open Access i DiVA

Fulltekst mangler i DiVA

Andre lenker

Forlagets fulltekst

Søk i DiVA

Av forfatter/redaktør
Blomberg, Margareta R. A.Barth, Andreas
Av organisasjonen
I samme tidsskrift
Journal of Physical Chemistry B

Søk utenfor DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric

doi
urn-nbn
Totalt: 21 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • 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