Efficient ribosomal peptidyl transfer critically relies on the presence of the ribose 2'-OH at A2451 of 23S rRNA

The ribosomal peptidyl transferase center is a ribozyme catalyzing peptide bond synthesis in all organisms. We applied a novel modified nucleoside interference approach to identify functional groups at 9 universally conserved active site residues. Owing to their immediate proximity to the chemical center, the 23S rRNA nucleosides A2451, U2506 and U2585 were of particular interest. Our study ruled out U2506 and U2585 as contributors of vital chemical groups for transpeptidation. In contrast the ribose 2'-OH of A2451 was identified as the prime ribosomal group with potential functional importance. This 2'-OH renders almost full catalytic power to the ribosome even when embedded into an active site of six neighboring 2'-deoxyribose nucleosides. These data highlight the unique functional role of the A2451 2'-OH for peptide bond synthesis among all other functional groups at the ribosomal peptidyl transferase active site.     

Efficient synthesis of enantiomerically pure (S)-δ-azaproline starting from (R)-α-hydroxy-γ-butyrolactone via the Mitsunobu reaction

The synthesis of enantiomerically pure orthogonally protected δ-azaproline has been performed in five steps including two successive Mitsunobu reactions starting from benzyloxycarbonylaminophthalimide and the (R)-α-hydroxy-γ-butyrolactone.     

A multiplicity result for a special class of gradient-type systems with non-differentiable term

We prove the existence of multiple solutions of certain systems of hemivariational inequalities, using a recent minimax result of B. Ricceri. We apply both our main theorem and the principle of symmetric criticality to obtain multiple solutions of systems of hemivariational inequalities defined on certain Sobolev spaces.     

Proteomic Analysis of Plasma Membrane Vesicles

A simple and scalable method is presented for harvesting, purification, and on‐chip processing of mammalian plasma membrane vesicles (PMVs) optimized for downstream proteome analysis. After immobilization on a microfluidic flowcell of PMVs, the embedded membrane proteins are proteolytically digested, and the peptides harvested and analyzed by LC‐MS/MS. Over 93 % of the detected proteins are plasma‐membrane‐derived.

     

A Microreactor with Thousands of Subcompartments: Enzyme‐Loaded Liposomes within Polymer Capsules

Fully loaded : Noncovalent anchoring of liposomes into polymer multilayered films with cholesterol‐modified polymers allows the preparation of capsosomes—liposome‐compartmentalized polymer capsules (see picture). A quantitative enzymatic reaction confirmed the presence of active cargo within the capsosomes and was used to determine the number of subcompartments within this novel biomedical carrier system.

     

Statistical Encounters with Complex B-Splines

Complex B-splines as introduced in Forster et al. (Appl. Comput. Harmon. Anal. 20:281–282, 2006) are an extension of Schoenberg’s cardinal splines to include complex orders. We exhibit relationships between these complex B-splines and the complex analogues of the classical difference and divided difference operators and prove a generalization of the Hermite–Genocchi formula. This generalized Hermite–Genocchi formula then gives rise to a more general class of complex B-splines that allows for some interesting stochastic interpretations.      

Hyperbranched polyesters: End group modification and properties

Several hyperbranched polyesters have been prepared in a one-pot polycondensation reaction. Molecular weights, viscosities and rheological behavior of these polymers have been characterized. The influence of their terminal groups on the properties and their behavior in blends will be discussed.     

Polyelectrolyte-surfactant complexes containing photolabile diazosulfonate chromophores

Low-molar-mass surfactants (S) and polyelectrolytes (PE) containing diazosulfonate chromophores which are photo-labile and electrically charged were used for the formation of polyelectrolyte/surfactant complexes (PESC) in combination with commonly used polyelectrolytes and surfactants. The stable complexes are no longer water-soluble and were characterized by means of nuclear magnetic resonance spectroscopy and in some cases by means of gel-permeation chromatography measurements. Complexes with a 1 : 1 stoichiomctry with respect to charge are formed. Ultraviolet irradiation of the photo-labile PESC resulted in the loss of the ionic interactions.