cassava7
Senior Member (Voting Rights)
Single-molecule reading of proteins
Modern DNA-sequencing methods can interrogate single molecules in extremely high throughput, but protein sequencing typically uses ensemble techniques and requires larger amounts of relatively pure material.
Reed et al. generated a set of labeled proteins that recognize the first few amino acids at the N terminus of a peptide immobilized on an optical chip. Transient binding yields spectral signals and association and dissociation rates that can be used to identify the terminal amino acid.
Multiple amino acids on a single molecule can then be read by adding a protease that gradually reveals the next amino acid at the terminus. —MAF
Abstract
Studies of the proteome would benefit greatly from methods to directly sequence and digitally quantify proteins and detect posttranslational modifications with single-molecule sensitivity.
Here, we demonstrate single-molecule protein sequencing using a dynamic approach in which single peptides are probed in real time by a mixture of dye-labeled N-terminal amino acid recognizers and simultaneously cleaved by aminopeptidases. We annotate amino acids and identify the peptide sequence by measuring fluorescence intensity, lifetime, and binding kinetics on an integrated semiconductor chip.
Our results demonstrate the kinetic principles that allow recognizers to identify multiple amino acids in an information-rich manner that enables discrimination of single amino acid substitutions and posttranslational modifications.
With further development, we anticipate that this approach will offer a sensitive, scalable, and accessible platform for single-molecule proteomic studies and applications.
https://www.science.org/doi/10.1126/science.abo7651
Modern DNA-sequencing methods can interrogate single molecules in extremely high throughput, but protein sequencing typically uses ensemble techniques and requires larger amounts of relatively pure material.
Reed et al. generated a set of labeled proteins that recognize the first few amino acids at the N terminus of a peptide immobilized on an optical chip. Transient binding yields spectral signals and association and dissociation rates that can be used to identify the terminal amino acid.
Multiple amino acids on a single molecule can then be read by adding a protease that gradually reveals the next amino acid at the terminus. —MAF
Abstract
Studies of the proteome would benefit greatly from methods to directly sequence and digitally quantify proteins and detect posttranslational modifications with single-molecule sensitivity.
Here, we demonstrate single-molecule protein sequencing using a dynamic approach in which single peptides are probed in real time by a mixture of dye-labeled N-terminal amino acid recognizers and simultaneously cleaved by aminopeptidases. We annotate amino acids and identify the peptide sequence by measuring fluorescence intensity, lifetime, and binding kinetics on an integrated semiconductor chip.
Our results demonstrate the kinetic principles that allow recognizers to identify multiple amino acids in an information-rich manner that enables discrimination of single amino acid substitutions and posttranslational modifications.
With further development, we anticipate that this approach will offer a sensitive, scalable, and accessible platform for single-molecule proteomic studies and applications.
https://www.science.org/doi/10.1126/science.abo7651