M & L Jaargang 1/3

RedactioneelA.M. Delepierre Het arrondissement Veurne: een globale benadering. [The district of Veurne: a comprehensive approach of historic building inventory.]M. Lion en M. Ramakers De kustarchitectuur in de Westhoek of het bouwen aan de rand van de zeefascinatie. [Coastal architecture in the Westhoek, or Building on the Verge of Sea-fascination.]Guido Ostyn De Frans-Belgische Moeren. [The French-Belgian Moeren.]Jo De Schepper De Franse-Belgische Moeren: enkele gegevens aangaande de windgemalen. [The French-Belgian Moeren: some data about the wind-pumpingengines.]Herman Stynen Jozef Viérin (1872-1949). [Jozef Viérin (1872-1949), profile of an architect.]P. Roose Het Van Peteghem-orgel (1838) in het voormalig Sint-Jans-Gasthuis (thans Bisschoppelijk College) te Veurne. [The Van Peteghem organ (1838) in the former Saint Johns hospital (now Episcopal College) in Veurne.]SummaryM&L Binnenkran

Peptide Conformer Acidity Analysis of Protein Flexibility Monitored by Hydrogen Exchange†

ABSTRACT: The amide hydrogens that are exposed to solvent in the high-resolution X-ray structures of ubiquitin, FK506-binding protein, chymotrypsin inhibitor 2, and rubredoxin span a billion-fold range in hydroxide-catalyzed exchange rates which are predictable by continuum dielectric methods. To facilitate analysis of transiently accessible amides, the hydroxide-catalyzed rate constants for every backbone amide of ubiquitin were determined under near physiological conditions. With the previously reported NMR-restrained molecular dynamics ensembles of ubiquitin (PDB codes 2NR2 and 2K39) used as representations of the Boltzmann-weighted conformational distribution, nearly all of the exchange rates for the highly exposed amides were more accurately predicted than by use of the high-resolution X-ray structure. More strikingly, predictions for the amide hydrogens of the NMR relaxation-restrained ensemble that become exposed to solvent in more than one but less than half of the 144 protein conformations in this ensemble were almost as accurate. In marked contrast, the exchange rates for many of the analogous amides in the residual dipolar coupling-restrained ubiquitin ensemble are substantially overestimated, as was particularly evident for the Ile 44 to Lys 48 segment which constitutes the primary interaction site for the proteasome targeting enzymes involved in polyubiquitylation. For both ensembles, “excited state ” conformers in this active site region having markedly elevated peptide acidities are represented at a population level that is 102 to 103 abov

High resolution liquid NMR and magic angle spinning

Magic angle spinning (MAS) has since long been proven powerful in the studies of heterogeneous samples such as powdered solids, compartmentalized liquid samples, or heterogeneous solid-liquid mixtures. Recently it has been shown that higher resolution could be achieved if high-resolution magnetic-susceptibility-matching probe (Nano.nmr probe)technology was used in conjunction to MAS. In this paper we illustrate the possibilities of generating high resolution spectra of liquid using the Nano.nmr probe for the study of macromolecules in solution

Conformation of the C-terminal secretion signal of the Serratia marcescens haem acquisition protein (HasA) in amphipols solution, a new class of surfactant

The conformation of a peptide, CterH, encompassing the last 56 C-terminal residues of Serratia marcescens haem acquisition protein HasA was examined by Circular Dichroism in amphipols solutions. The peptide, which contains the secretion signal of HasA, is unstructured in aqueous solution and adopts an helical structure upon the amphiphilic polymer addition. Furthermore, the helical content of CterH is modulated by the ionic strengh of the solution. These results are compared to those obtained with CterH in membrane mimetic environments

The interface between microbiology and structural biology as viewed by nuclear magnetic resonance.

Nuclear magnetic resonance (NMR) spectroscopy is one of two principal experimental techniques used in structural biology. It can be used to determine structures at atomic resolution and to investigate the dynamics of macromolecules and intermolecular interactions. We aim to give an overview of the use of modern high resolution NMR methodology in microbiology

Mononucleotides

The experimental conditions of removing paramagnetic impurities, in order to make T1 measurments of nucleotides 31P, by filtration through a chelating resin or by addition of a water soluble cleating reagent, are discussed

Adiabatic TOCSY MAS in liquids.

The effect of magic angle spinning (MAS) of liquids upon the performance of various isotropic mixing sequences is investigated. Although the mathematical formalism for isotropic mixing under MAS conditions is similar for both liquids and solids, the mechanism through which the coherence transfer is disturbed is different. In liquids, the use of sample spinning in the presence of both RF and magnetic-field inhomogeneities introduces a modulation of the effective field, which compromises the performance of the conventional mixing sequences. This effect is further amplified by supercycles, which normally improve the performance of the mixing and decoupling experiments. It is demonstrated that adiabatic mixing sequences are less susceptible to such modulations and perform considerably better in TOCSY MAS experiments. The best performance of TOCSY MAS is observed under the rotational resonance condition when the sample appears static in the nutation reference frame

Solution structure of the orphan nuclear receptor rev-erb beta response element by 1H, 31P NMR and molecular simulation*.

International audienceRev-erb beta is an orphan receptor that binds as a homodimer or as a monomer to DNA. The solution structure of the non-palindromic 15 bp DNA duplex d(TAGAATGTAGGTCAG), the response element of Rev-erb beta for monomeric binding, was determined by 1H and 31P NMR, energy minimization with NMR-derived restraints for distances and NOE back-calculation methods. The refined final structures have the typical overall features of B-type DNA. However, titration of this 15 bp duplex with ReDBD, the DNA binding domain of Rev-erb beta, showed large shifts of imino protons and 31P signals, suggesting major conformational changes