Doctoral students seminar (January 16, 2018)

Geometrical stiffness studied by a coarse grained homopolymer model

by Benno Werlich

Morphologies of biopolymers depend on the interaction energies and on stiffness. We use a coarse grained homopolymer model to study geometrical stiffness as bond length variation. Therefore we show a wide range of stable structures which are known from different stiffness approaches and also from experiments. With the help of canonical and microcanonical analysis we created a state diagram for a broad range of stiffness from flexible to very stiff chains. Simulations were performed by Stochastic Monte Carlo Simulations (SAMC).

 

Location: MLU, Von-Danckelmann-Platz 3, SR E.04
Time: 3.30pm-5.00pm

Talk by Ruth Bärenwald at MLU (December 12, 2017)

Solid state NMR investigations and MD simulations of amphiphilic triblock copolymers in lipid bilayers

Pluronics are triblock copolymers widely used in pharmacological industry that consist of hydrophilic poly(ethylene oxide) end blocks and a hydrophobic poly(propylene oxide) middle block. Depending on the lengths of the different blocks, Pluronics can influence membrane properties in a variety of ways.

Using solid-state nuclear magnetic resonance (NMR), we investigated the structure and dynamics of different Pluronics interacting with a number of phosphatidylcholine membranes with variable bilayer thickness and acyl chain saturation. Continue reading “Talk by Ruth Bärenwald at MLU (December 12, 2017)”

Talk by S. Link at MLU (November 14, 2017)

UV-B induced changes of eye-lens crystallins

Age related cataract is the major cause of blindness worldwide. With the age of 75 years, more than 50% of all people are affected and so far, surgery is the only effective treatment available. For this reason it is important to understand the complex system of the eye lens especially effects of aging like chronic UV-B irradiation.

Many modifications of crystallins by UV-B on already aggregated and destroyed protein have been found. So far, changes in the soluble fractions of the protein are not well investigated. Answering this question, different techniques of solution NMR have been applied to native and irradiated hgD-crystallin to identify and characterize a modified but still soluble state of the protein. This would highlight the first structural changes on the transition from functional soluble protein to dysfunctional aggregates.

Location: MLU, Von-Danckelmann-Platz 3, SR 1.06
Time: 3.30pm

Talk by F. Frenzel at UL (October 24, 2017)

Molecular Dynamics and Charge Transport in highly-conductive Polymeric Ionic Liquids

Glassy dynamics and charge transport are studied for the polymeric ionic liquid (PIL) poly[tris(2-(2-methoxyethoxy)ethyl)ammonium acryloxypropyl sulfonate] (PAAPS) with varying molecular weight (9700, 44200, 51600, and 99500 g/mol) by broadband dielectric spectroscopy (BDS) in a wide frequency (10−2−107 Hz) and temperature range (100−400 K) and by DSC- and AC-chip calorimetry.

The dielectric spectra are characterized by a superposition of (i) relaxation processes, (ii) charge transport, and (iii) electrode polarization. Continue reading “Talk by F. Frenzel at UL (October 24, 2017)”