Researchers at the University of Pennsylvania have developed a method that allows gene sequencing a strand of DNA's bases threaded through a nanoscopic hole.
In their new study, the scientists have also shown that this new technique can be applied to learn more about the structure of proteins. The new research paper was published in the journal ACS Nano.
The existing methods for this type of analysis are labor intensive. They typically involve collecting of large quantities of the protein, requiring often protein modification. These requirements are limiting these previous methods' usefulness for understanding the behavior of the protein in its natural state.
The new translocation technique designed by Penn researchers allows for the study of individual proteins without the need to modify them. This way could be analyzed samples taken from a single individual, opening applications for research and disease diagnostics.
The study was led by a professor in the School of Arts & Sciences' Department of Physics & Astronomy, Marija Drndić, a postdoctoral researcher in her lab, David Niedzwiecki, as well as the professor in Penn Arts & Sciences' Department of Chemistry, Jeffery G. Saven.
The Penn team's technique is based on Drndić's previous studies on nanopore gene sequencing. The professor researched a method to distinguish the bases in a strand of DNA based on the different percent of the blocked aperture as they pass through a nanoscopic pore. According to the researcher, different silhouettes allow different amounts of ionic liquid to pass through. Electronics surrounding the pore measure the change in ion flow. Each base can be correlated with the peaks and valleys of that signal.
Drndić and her research team have experimented with applying this technique to various nanoscale structures and biological molecules. In collaboration with Saven's group, the research team tested their pores on biological molecules.
According to Saven, there are many proteins that have very small dimensions that make them more difficult to manipulate than a strand of DNA. The research team is interested in learning about the structure of the protein and being able to distinguish whether the protein exists as a monomer, dimer, or an aggregate known as an oligomer.
This new method allows scientists to collect the needed amount of data and study the proteins one at the time as they pass through the nanopore. Studying protein one at the time is important, according to scientists, since this way they can be studied as they naturally exist in the body.