TU Darmstadt / ULB / TUbiblio

NMR localization of protons in critical enzyme hydrogen bonds

Sharif, S. ; Fogle, E. ; Toney, M. D. ; Denisov, G. S. ; Shenderovich, I. G. ; Buntkowsky, G. ; Tolstoy, P. M. ; Huot, M. C. ; Limbach, H. H. (2007)
NMR localization of protons in critical enzyme hydrogen bonds.
In: Journal of the American Chemical Society, 129 (31)
Article, Bibliographie

Abstract

Using N-15 NMR spectroscopy and hydrogen bond correlations, we have localized a mechanistically critical proton in aspartate aminotransferase in microcrystals and aqueous solution. It is in a H-bond between a carboxylate O of Asp222 and the pyridine nitrogen of pyridoxal-5'-phosphate. At neutral pH in water, aspartate and pyridine are unprotonated, but they share a proton in the enzyme. It is shown that such a binuclear base is typical for acid-base interactions in aprotic polar solvents. Active site H-bonds to Asp222 assist protonation of the pyridine nitrogen in the enzyme, which is considered a prerequisite for catalytic activity. We also show that acid-base behavior in enzymes should be modeled using aprotic polar solvents rather than aqueous solutions.

Item Type: Article
Erschienen: 2007
Creators: Sharif, S. ; Fogle, E. ; Toney, M. D. ; Denisov, G. S. ; Shenderovich, I. G. ; Buntkowsky, G. ; Tolstoy, P. M. ; Huot, M. C. ; Limbach, H. H.
Type of entry: Bibliographie
Title: NMR localization of protons in critical enzyme hydrogen bonds
Language: English
Date: 2007
Journal or Publication Title: Journal of the American Chemical Society
Volume of the journal: 129
Issue Number: 31
URL / URN: http://apps.webofknowledge.com/full_record.do?product=WOS&se...
Abstract:

Using N-15 NMR spectroscopy and hydrogen bond correlations, we have localized a mechanistically critical proton in aspartate aminotransferase in microcrystals and aqueous solution. It is in a H-bond between a carboxylate O of Asp222 and the pyridine nitrogen of pyridoxal-5'-phosphate. At neutral pH in water, aspartate and pyridine are unprotonated, but they share a proton in the enzyme. It is shown that such a binuclear base is typical for acid-base interactions in aprotic polar solvents. Active site H-bonds to Asp222 assist protonation of the pyridine nitrogen in the enzyme, which is considered a prerequisite for catalytic activity. We also show that acid-base behavior in enzymes should be modeled using aprotic polar solvents rather than aqueous solutions.

Uncontrolled Keywords: coli aspartate-aminotransferase escherichia-coli carboxylic-acids 10-18-ppm range h-1 resonances concanavalin-a model systems active-site solid-state pyridoxal
Additional Information:

196LW Times Cited:35 Cited References Count:31

Divisions: 07 Department of Chemistry
07 Department of Chemistry > Eduard Zintl-Institut > Physical Chemistry
Date Deposited: 27 Oct 2014 20:49
Last Modified: 29 May 2019 12:48
PPN:
Export:
Suche nach Titel in: TUfind oder in Google
Send an inquiry Send an inquiry

Options (only for editors)
Show editorial Details Show editorial Details