Berlin 2015 – scientific programme
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BP: Fachverband Biologische Physik
BP 41: Protein structure and dynamics I
BP 41.2: Talk
Thursday, March 19, 2015, 10:00–10:15, H 1058
Insulin at the air water interface: Monomers or dimers? — •Sergio Mauri1,2, Tobias Weidner2, and Heike Arnolds1 — 1Surface Science Research Centre, University of Liverpool, UK — 2Max Planck institute for polymer research, Mainz, Germany
The adsorption of insulin at surfaces is a ubiquitous problem of interest in various fields of biotechnology and pharmaceutical applications. Studying protein structure at surfaces is generally though a challenging task: Conventional techniques like IR and Raman spectroscopy, can achieve surface sensitivity, but different states (aggregates) of the same protein have often similar spectral signatures. Here we combine sum frequency spectroscopy (SFG) spectroscopy with spectra calculations to identify specific oligomeric species of insulin at interfaces. In particular we study the air/water interface due to its relevance in the production, storage and delivery of insulin-based medications. Insulin is present in Nature mainly as hexamers, dimers and monomers. While the first two are stable, monomers do denaurate and aggregate under certain conditions. Eventually, monomers further aggregate in amyloid-like structures, which are undesired. We find that only insulin monomers segregate at the air/water interface. This advance helps to solve the long standing puzzle of insulin fibril formation. The versatility of the proposed experimental approach could be used to investigate a large variety of proteins and surfaces.
- Mauri et al., PCCP, 2014, 16, 26722-26724