In the quest for a breakthrough technology facilitating seamless protein sequencing, scientists have engaged in a fierce competition. Professor Giovanni Maglia, a luminary in Chemical Biology at the University of Groningen, has emerged as the key innovator, uncovering the vital component that had eluded researchers: a method to usher proteins through a nanopore, thereby enabling straightforward protein sequencing using a portable, handheld device.
The revolution ignited by DNA sequencing has transformed our comprehension of life itself, and the sequencing of proteins stands as the next coveted milestone. Professor Maglia elucidates, “While DNA largely remains static, the vital processes within our cells are orchestrated by proteins, which execute the actual work. A profound understanding of proteins promises deeper insights into the inner workings of our bodies.”
Presently, handheld devices capable of DNA sequencing are commercially available. These devices leverage nanopore technology, where a solitary DNA strand is drawn through a minuscule aperture, or nanopore, within a membrane. As the strand traverses this channel, it is possible to decipher the sequence of constituent building blocks in the DNA strand.
Progress has been made in adapting this nanopore technology for protein sequencing, but the challenge lay in transporting a lengthy protein through the narrow aperture in a manner akin to a DNA strand. As Professor Maglia analogizes, “It’s akin to dealing with cooked spaghetti; these elongated strands resist organization and resist being coerced through such a minute opening.”
Single-stranded DNA shares some resemblance with cooked spaghetti but can be propelled through the nanopore via an electric field due to the DNA’s inherent electrical charge. Proteins, on the other hand, exhibit a weaker charge and can bear either a positive or negative charge. As Professor Maglia explains, “Proteins and DNA are inherently dissimilar, necessitating an adaptation of the technology.”
To surmount this challenge, Maglia employed a solution containing electrically charged particles, or ions, which could be guided through the nanopore by an electric field. In doing so, these ions carried the protein along with them. This was by no means a trivial achievement, as Maglia elaborates, “We were uncertain whether the flow would be forceful enough. Moreover, these ions have an inclination to move in both directions. However, by affixing a significant charge to the nanopore itself, we successfully imposed a directional flow.”
Maglia devised a system with the most potent flow achievable without the presence of proteins. In collaboration with researchers from the University of Rome Tor Vergata, computer simulations were conducted, revealing that the force generated by this flow upon a protein was akin to the force exerted by the electric field on DNA. Maglia then put this method to the test with a challenging protein, one replete with negative charges, predisposing it to move counter to the flow. Astonishingly, even in this case, the flow proved robust enough to usher the protein through the nanopore.
“Previously, only proteins that were easy to thread through were subject to analysis. However, we chose one of the most challenging proteins for our experimentation, and it succeeded! This unequivocally demonstrates that there are no fundamental constraints impeding protein sequencing any longer,” Maglia exclaims. With the establishment of his new venture, Portal Biotech, Maglia intends to make the nanopore technology developed in his laboratory accessible to a broad spectrum of users, including laboratories and medical practitioners. “With this latest research breakthrough, we’ve acquired the missing puzzle piece essential to actualizing protein sequencing,” he concludes. The findings from this research were published in Nature Biotechnology.
Source: University of Groningen