Global Attractor of a Dissipative Fractional Klein Gordon Schrödinger System

Journal of Dynamics and Differential Equations - In this paper we study the local and global well posedness of a fractional dissipative Klein–Gordon–Schrödinger type system in...     

Synthesis and Evaluation of Non-Hydrolyzable Phospho-Lysine Peptide Mimics

The intrinsic lability of the phosphoramidate P−N bond in phosphorylated histidine (pHis), arginine (pHis) and lysine (pLys) residues is a significant challenge for the investigation of these post-translational modifications (PTMs), which gained attention rather recently. While stable mimics of pHis and pArg have contributed to study protein substrate interactions or to generate antibodies for enrichment as well as detection, no such analogue has been reported yet for pLys. This work reports the synthesis and evaluation of two pLys mimics, a phosphonate and a phosphate derivative, which can easily be incorporated into peptides using standard fluorenyl-methyloxycarbonyl- (Fmoc-)based solid-phase peptide synthesis (SPPS). In order to compare the biophysical properties of natural pLys with our synthetic mimics, the pK_a values of pLys and analogues were determined in titration experiments applying nuclear magnetic resonance (NMR) spectroscopy in small model peptides. These results were used to compute electrostatic potential (ESP) surfaces obtained after molecular geometry optimization. These findings indicate the potential of the designed non-hydrolyzable, phosphonate-based mimic for pLys in various proteomic approaches.     

Chromatographic and luminescence properties of a 7-aminocoumarin derivative with peroxyoxalate chemiexcitation

A new derivatizing reagent for amines, luminarine 1, is described, and tested as its pentylamine derivative. Chromatographic separation in both normal- and reversed-phase systems was achieved. With fluorescence detection, the limit of detection was in the subpicomole range. With the optimization procedure for chemiluminescence detection, the limit of detection was 1 fmol in the normal-phase system (using bis (2,4-dinitrophenyl) oxalate and hydrogen peroxide), and 6 fmol in the reversed-phase system (using bis (2,4,6-trichlorophenyl) oxalate and hydrogen peroxide ), but the coefficient of variation was lower for the latter system (3.4% vs. 5.8%).