Mittwoch, 6. Juni 2007

Solid State NMR Position

Solid State NMR Position

Project: Structural Investigations of b-sheet polymer hybrids using advanced solid-state NMR techniques.

Job description
Within the Physical Chemistry / solid-state NMR group of the Institute for Molecules and Materials, there is an opening for a graduate student for the study of biomimetic materials using advanced solid-state NMR techniques. The project will be dedicated to detailed structural investigations of b-sheet polymer hybrids developed in the synthetic groups in the IMM.

Requirements
Required education/skills:
We are looking for an enthusiastic researcher with a Master’s degree in Chemistry with adequate theoretical and experimental skills. We prefer candidates with a good team spirit, who like to work in an internationally oriented environment and are able to collaborate with our partner groups on the crossroads between chemistry and physics.

Conditions of employment
Estimated maximum salary per month: € 2000 - 2500

* Employment basis: Temporary for specified period
* Duration of the contract: Starts for a period of one year, with a possible prolongation till 4 years
* Maximum hours per week: 40

Further Information / application
Further information can be obtained from Prof. dr. A.P.M. Kentgens (e-mail a.kentgens@nmr.ru.nl, phone +31-24-3652078/3652004).
Written applications, including curriculum vitae, summary of research interest and experience, should be directed to: Mrs. A. Schröder, Faculty of Science, Personnel Department, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands, or via e-mail pz@science.ru.nl

Project details
The aim of Institute for Molecules and Materials is to conduct research and train undergraduate and graduate students in the field of functional- molecular structures and materials. There is an emphasis on understanding and controlling complexity in order to be able to design new functionality in these systems. This research area can be divided into two main themes: bio-inspired systems and nano/mesoscopic structures. Covering both experimental and theoretical physics and chemistry, and harboring skills in state-of-the-art analytical and synthetic techniques, the groups that constitute the IMM possess expertise in all areas needed to explore these fields. Nuclear magnetic resonance (NMR) research plays an important role in the research of the IMM. The nuclear spin is a universal probe for local structural information which can contribute significantly to the level of understanding if applied under the proper conditions. The IMM has excellent solid-state NMR facilities, including Chemagnetics CMX Infinity 300, 400 and 600 MHz spectrometers, a homebuilt 180 MHz spectrometer and access to a Varian Inova 800 spectrometer with solids capabilities. In collaboration with the Nijmegen high magnet field laboratory 30 T Bitter magnet is being optimized for magnetic resonance experiments. Finally funds have been acquired to set up an international solid-state NMR facility including a new wide-bore 850 MHz NMR spectrometer that should arrive in 2008.
Materials scientists at IMM have become increasingly interested in combining natural and synthetic polymers into hybrid polymeric structures. The functionality of (fragments of) biopolymers can be integrated with the synthetic versatility and adaptability of synthetic polymers, thus creating a new class of materials harnessing the best of both worlds. One of the most common peptide motifs that have been introduced in polymer peptide hybrid materials is the b-sheet. Reasons for this are the synthetic accessibility of b-sheet forming peptides, small sequences already display the desired properties, and their relevance in structural proteins such as silk, in which (anti-parallel) b-sheets are responsible for crystallinity and hence stiffness of these biopolymers. More mobile regions are also present giving the material elasticity resulting in a material that is both very strong and smooth. The different physical properties of various silks arise from a variation in the protein’s primary and secondary structure.
IMM researchers (Prof. van Hest et al.) are working on controlled assembly of macromolecular -sheet fibrils. The attachment of poly(ethylene glycol) end blocks to a central poly(AG)3EG b-sheet block prevents the macroscopic aggregation of the b-sheet blocks into needle-shaped lamellar crystals. Instead crystallization results in well-defined fibrils. The rationale behind attachment of synthetic polymer blocks at the N- and C-termini was to restrict macroscopic crystallization and to preserve translation of the b-sheet design characteristics of width, height, and surface functionality into self-assembled structures. It is the subject of this study to develop and apply advanced solid-state NMR techniques to gain in-depth knowledge of the structure of these materials in relation to their functionality.
In some cases aggregation of b-sheet peptides is an undesired feature. This is particularly
true for fibril formation of b-amyloid peptide, the primary component of amyloid plaques in Alzheimer’s disease. One possibility is to prevent the aggregation of A by short peptide sequences. The goal is to study binding of the elongated peptides to the A monomers during the formation of oligomers and fibrils by solid-state NMR.