From natural to artificial channels

PhD ceremony: Mr. E. Halža, 11.00 uur, Doopsgezinde Kerk, Oude Boteringestraat 33, Groningen

Title: From natural to artificial channels

Promotor(s): prof. B.L. Feringa

Faculty: Mathematics and Natural Sciences

The thesis of Erik Halža is focusing on the modification of naturally occurring transport systems, pores and channels, with small organic molecules in order to control their function and properties. On the other hand completely artificial channels build out of small organic molecules are discussed by him as well.

The cell is the structural and functional unit of all known living organisms. Each cell is able of self-containing and self-maintaining: it can take in nutrients, convert these nutrients into energy, carry out specialized functions, and reproduce as necessary.

All cells are surrounded by a closed membrane that defines the cell. Even within the cell, membranes play key roles in compartmentalization of biochemical products and processes. These membranes prevent molecules generated inside the cell from leaking out and unwanted molecules from diffusing in; yet they also contain transport systems for carrying specific molecules inside and outside of the cell.

Halža has modified alamethicin, naturally occurring pore forming peptide with light switchable azobenzene molecule in order to control its function by light. The functional size of SecYEG pore has been probed by him by attaching rigid spherical molecules to Outer membrane protein A.

Also Halža has modified the mechanosensitive channel of large conductance with redox- and pH-sensitive labels in order to control its function electrochemically or by changing pH of the environment. The synthesis of artificial channel forming molecules has been described by Halža as well as electrophysiological and cryo-TEM studies. Finally, the last chapter is focusing on the synthesis and properties of iron(II) and diarylethene switch complex in order to control the magnetic properties of this complex by light.