Sequence-dependent Mechanics of Collagen Model Peptides
Job Offer from December 19, 2018
Collagen is the main constituent of connective tissues such as bone, cartilage, tendon and skin. It has recently been shown that water is an integral component of collagen and that the water content directly affects the mechanical properties of collagen structures. For example, it has been demonstrated that collagen fibers contract upon a decrease in the osmotic pressure. This contraction generates large forces and may be biologically relevant for controlling the mechanical properties of tissues. Preliminary results suggest that this osmotic pressure sensitivity is programmed into the collagen sequence, hinting at molecular level control of collagen mechanics. To investigate this sequence-structure-function relationship in more detail, short collagen mimetic peptides (CMPs) are powerful model systems. These CMPs self-assemble into stable triple-helical structures, which resemble the fundamental building block of collagen.
In this project you will synthesize and analyze a set of CMPs with defined sequence to investigate the interplay between amino acid sequence and osmotic pressure induced structural changes. In more detail:
- You will use solid phase peptide synthesis to obtain host-guest peptides of the basic structure (PPG)4-XXGXXG-(PPG)4, where the guest sequence represents the sequence of interest while the host sequences are required for triple helix folding and stabilization.
- You will purify these peptides with high-performance liquid chromatography (HPLC) and perform basic characterization with mass spectrometry and circular dichroism (CD) spectroscopy) to verify the correct sequence and structure.
- You will then investigate these peptides with infrared (IR) and Raman spectroscopy at different relative humidities to determine the effect of osmotic pressure on the triple helical conformation of these peptides.
The obtained structural information is subsequently correlated with the mechanical properties of these peptides using Molecular Dynamics simulations, performed in the group of our collaborators.
You are studying chemistry and are familiar with solid phase peptide synthesis as well as with spectroscopic methods, such as IR and CD spectroscopy. You are open and interested in learning new methods and applying them in an interdisciplinary context. We offer the possibility to participate in an ongoing, collaborative research project at an international research institute. Independent thinking, team spirit and communication are crucial for a successful development of the project. You should further have a good level of English.