On Molecular Statics Simulation of Ferroelectric Barium Titanate

The present contribution deals with the atomistic modelling of ferroelectric barium titanate. In this context a core-shell model is implemented in a Molecular Static algorithm. Furthermore, Coulomb forces are simulated by the Wolf summation method in order to allow for a small cut off radius. We discuss the core-shell model, molecular statics as a finite elements approach and present some numerical results. (© 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

In vitro selection of functional lantipeptides

In this report we present a method to identify functional artificial lantipeptides. In vitro translation coupled with an enzyme-free protocol for posttranslational modification allows preparation of more than 10(11) different lanthionine containing peptides. This diversity can be searched for functional molecules using mRNA-lantipeptide display. We validated this approach by isolating binders toward Sortase A, a transamidase which is required for virulence of Staphylococcus aureus. The interaction of selected lantipeptides with Sortase A is highly dependent on the presence of a (2S,6R)-lanthionine in the peptide and an active conformation of the protein.     

Neutron bound beta-decay: BOB

Frozen solution samples were made from gold chloride and KAu(CN)₂ solvated with TBP/xylene. The ¹⁹⁷Au M?ssbauer parameters were similar to those same species as frozen solutions or adsorbed onto activated carbon. Solvated samples from EuO dissolved in HCl or H₂SO₄ and frozen gave characteristic Eu(III) spectra. All the spectra were consistent with bonding to the TBP being through hydronium ions or water molecules.     

On the birational anabelian program initiated by Bogomolov I

Recall that a program initiated by Bogomolov in 1990 aims at reconstructing function fields K|k with td(K|k)>1 and k algebraically closed from the maximal pro-ℓ abelian-by-central Galois group P^c  _K\Pi ^{\hbox to1pt{}{\rm c}_{\phantom {g}}}_{K} of K, where ℓ is any prime number ≠char(k). In this paper we complete that program in the case k is an algebraic closure of a finite field.     

Epicatechin B-ring conjugates: first enantioselective synthesis and evidence for their occurrence in human biological fluids

Herein, the first enantioselective total synthesis of a number of biologically relevant (-)-epicatechin conjugates is described. The success of this synthesis relied on (i) optimized conditions for the stereospecific cyclization step leading to the catechin C ring; on (ii) efficient conjugation reactions; and on (iii) optimized deprotection sequences. These standard compounds have been subsequently used to elucidate for the first time the pattern of (-)-epicatechin conjugates present in four different human biological fluids following (-)-epicatechin absorption.     

Electronic fine structure calculation of [Gd(DOTA)(H2O)]– using LF-DFT: The zero field splitting

Zerfo field splitting plays an important role in determining the electron spin relaxation of Gd(III) in solution. We understand the ZFS as an effect depending on the f electron structure and treat it in the framework of ligand field-density functional theory (LF-DFT). We apply this theory to calculate the ZFS of [Gd(DOTA)(H₂O)]^? from first principles, having an insight concerning the contributions determining the ZFS.     

Semi-Synthesis and Analysis of Chemically Modified Zif268 Zinc-Finger Domains

Total synthesis of proteins can be challenging despite assembling techniques, such as native chemical ligation (NCL) and expressed protein ligation (EPL). Especially, the combination of recombinant protein expression and chemically addressable solid-phase peptide synthesis (SPPS) is well suited for the redesign of native protein structures. Incorporation of analytical probes and artificial amino acids into full-length natural protein domains, such as the sequence-specific DNA binding zinc-finger motifs, are of interest combining selective DNA recognition and artificial function. The semi-synthesis of the natural 90 amino acid long sequence of the zinc-finger domain of Zif268 is described including various chemically modified constructs. Our approach offers the possibility to exchange any amino acid within the third zinc finger. The realized modifications of the natural sequence include point mutations, attachment of a fluorophore, and the exchange of amino acids at different positions in the zinc finger by artificial amino acids to create additional metal binding sites. The individual constructs were analyzed by circular dichroism (CD) spectroscopy with respect to the integrity of the zinc-finger fold and DNA binding.