Active Conformation Control of Unfolded Proteins by Hyperthermal Collision with a Metal Surface

作者：Rinke Gordon^*; Rauschenbach Stephan; Harnau Ludger; Albarghash Alyazan; Pauly Matthias; Kern Klaus

来源：Nano Letters, 2014, 14(10): 5609-5615.

DOI：10.1021/nl502122j

• Protein
• surface
• soft landing
• ion beam deposition
• scanning tunneling microscopy
• charge state
• persistence length

The physical and chemical properties of macromolecules like proteins are strongly dependent on their conformation. The degrees of freedom of their chemical bonds generate a huge conformational space, of which, however, only a small fraction is accessible in thermal equilibrium. Here we show that soft-landing electrospray ion beam deposition (ES-IBD) of unfolded proteins allows to control their conformation. The dynamics and result of the deposition process can be actively steered by selecting the molecular ion beam%26apos;s charge state or tuning the incident energy. Using these parameters, protein conformations ranging from fully extended to completely compact can be prepared selectively on a surface, as evidenced on the subnanometer/amino acid resolution level by scanning tunneling microscopy (STM). Supported by molecular dynamics (MD) simulations, our results demonstrate that the final conformation on the surface is reached through a mechanical deformation during the hyperthermal ion surface collision. Our experimental results independently confirm the findings of ion mobility spectrometry (IMS) studies of protein gas phase conformations. Moreover, we establish a new route for the processing of macromolecular materials, with the potential to reach conformations that would be inaccessible otherwise.

• 出版日期2014-10