Nanopore Technology Enables Detection of Structural Variations in Proteins

Scientists from the University of Oxford have developed a novel method for detecting structural variations on proteins using nanopore technologies. The innovative approach involves passing protein chains through engineered nanopores and analyzing subtle variations in structure through the modulation of tiny electrical currents. This approach could transform our understanding of how protein variants are linked to diseases and could pave the way for point-of-care diagnostics.

Proteins are essential components of human cells, with over 1,000,000 different structures known, generated through post-translational modifications (PTM). PTM introduces structural changes to proteins after they are transcribed from DNA, leading to numerous possible variations for the same protein chain. These variants play critical roles in biological processes within cells, making the mapping of protein variation invaluable for advancing our understanding of cellular functions.

The team’s innovative method was developed based on nanopore DNA/RNA sequencing technology. However, in this approach, protein chains are unfolded into linear chains and fed through tiny nanopores, allowing for the measurement of changes in electrical currents to identify structural variations. Different molecules cause distinct disruptions in the current, creating unique signatures for each modification.

The scientists successfully demonstrated the method's effectiveness in detecting three PTM modifications (phosphorylation, glutathionylation, and glycosylation) at the single-molecule level, even within long protein chains of over 1,200 residues. Remarkably, this method does not require the use of labels, enzymes, or additional reagents.

This new protein characterization method can be seamlessly integrated into existing portable nanopore sequencing devices, enabling researchers to rapidly build protein inventories of single cells and tissues. The potential applications are far-reaching, with point-of-care diagnostics becoming a possibility. This advancement could lead to personalized detection of specific protein variants associated with diseases like cancer and neurodegenerative disorders.

Professor Hagan Bayley, contributing author of the paper published in Nature Nanotechnology and co-founder of Oxford Nanopore Technologies, emphasized the immense promise this technology holds for advancing our understanding of cellular functions, molecular interactions, and its potential applications in personalized medicine, diagnostics, and therapeutic interventions. The ability to pinpoint and identify post-translational modifications and other protein variations at the single-molecule level opens new avenues for medical research and patient care.