Being able to study animals while they behave naturally is key in understanding the brain. Using carbon nanotube electrodes, the firing on individual neurons can be recorded, which can lead to further information about how the brain functions. These intracellular recordings in a freely behaving animal can give insight to how an animal learns and interacts with its environment. This carbon nanotube electrode has already been made in Dr. Donald’s lab, and my project is designing a protein to improve on the cell membrane penetration of these electrodes.
Currently, puncturing a cell with an electrode does not lend itself to longterm cellular recordings because the cell will be damaged. However, perhaps we could lessen this damage by creating a “seal” between the membrane and the electrode. Over at Stanford, Dr. Nick Melosh used a probe that would specifically interact with the hydrophilic-hydrophobic-hydrophilic properties of the lipid bilayer. The probe was hydrophilic with a hydrophobic band in the middle. When this probe pierced the bilayer, the hydrophobic band would interact with the hydrophobic tails of the phospholipids in the membrane, which made a “seal” between the probe and membrane. Greater force was required to move the probe past the membrane.
Using this idea of a hydrophobic “collar”, my project is to design proteins that could replicate this effect for a the carbon nanotube electrode. This would create the potential for longterm intracellular recordings. In my design I must consider the interaction between the protein and the carbon nanotube, interaction between the protein and the membrane, and interaction between the protein and other identical protein subunits.
My project is somewhat different than other projects in the lab in terms of the de novo design aspect and the carbon nanotube focus, but it fits the overall theme of using algorithms and protein design programs to solve problems.