An amino acid-specific binder selectively binds to a binding amino acid. A binder complex selectively identifies the binding amino acid and includes an adjunct attached to the amino acid-specific binder. The adjunct includes a taggant, protein, substrate, or chemical modifier. Selectively identifying an N-terminal amino acid includes anchoring a C-terminal end; contacting an N-terminal amino acid of the anchored analyte with the binder complex; selectively binding when the N-terminal amino acid includes the binding amino acid; producing, by the taggant of the tagged complex, a taggant signal; detecting the taggant signal; and identifying the N-terminal amino acid based on the taggant signal.

The invention relates to peptide mass fingerprinting technique for the proteins such as Human insulin and insulin analogs. The insulin analogues can vary at least by one amino acid, which is elusive to distinguish by currently available analytical methods. The invention further allows sequence confirmation of the peptide wherein the run time of the method is forty minutes. This method could be applied for molecules up to 50 kDa.

A method of mass spectrometry determines if a mutated variant of a target protein is present in a sample. The method includes subjecting the sample to fragmentation so as to cause the target protein to fragment to form second generation fragment ions, and then mass analysing these fragment ions to obtain spectral data. The method determines if a mutated variant is present in the sample by determining that an ion in the spectral data has a mass to charge ratio that differs from the mass to charge ratio of an ion that would be observed if the target protein was a normal unmutated version of the target protein, and by an amount that corresponds to a mass difference that would be caused by the target protein being a mutated variant of the target protein.

The present application relates to the field of protein sequencing, more particularly to protein profiling using massively parallel sequencing with single-molecule sensitivity. Methods, assays and reagents are provided for sequencing individual protein or polypeptide molecules. Also provided are methods and assays for the parallel sequencing of proteins or polypeptides. To this end, particular labeled probes are used that are reactive with the N-terminal amino acid of the polypeptide molecules and can be detected while still associated with the polypeptide(s).

An amino acid-specific binder selectively binds to a binding amino acid. A binder complex selectively identifies the binding amino acid and includes an adjunct attached to the amino acid-specific binder. The adjunct includes a taggant, protein, substrate, or chemical modifier. Selectively identifying an N-terminal amino acid includes anchoring a C-terminal end; contacting an N-terminal amino acid of the anchored analyte with the binder complex; selectively binding when the N-terminal amino acid includes the binding amino acid; producing, by the taggant of the tagged complex, a taggant signal; detecting the taggant signal; and identifying the N-terminal amino acid based on the taggant signal.

Methods and compositions for the manufacture and use of a detection apparatus based on one or more native biological nanopores are provided. Uses include, but are not limited to, detection and sequencing of nucleic acids.

Identifying proteins and peptides, and more specifically large-scale sequencing of single peptides in a mixture of diverse peptides at the single molecule level is an unmet challenge in the field of protein sequencing. Herein are methods for identifying amino acids in peptides, including peptides with unnatural amino acids. In one embodiment, the N-terminal amino acid is labeled with a first label and an internal amino acid is labeled with a second label. In some embodiments, the labels are fluorescent labels. In other embodiments, the internal amino acid is Lysine. In other embodiments, amino acids in peptides are identified based on the fluorescent signature for each peptide at the single molecule level.

A method and system for performing single molecule proteomics utilizing a nanopore sensor to measure an electronic signature of protein or peptide being transported through the nanopore from a first chamber to a second chamber. The protein's electronic signature is a function of ionic current over time. The method and system utilizing an agent, such as guanidinium chloride, to bind to the nanopore's interior and provide an electroosmotic force within the nanopore. The electroosmotic force, in some embodiments, enables stretching and unfolding of the protein during transport through the nanopore. The agent may also or alternatively induce the unfolding of the protein before transport through the nanopore and/or provide force moving the protein through the nanopore.

The present disclosure relates to a metalloprotein binder that specifically binds to a N-terminally modified peptide. Also provided herein is a method and related kits for treating or analyzing a peptide using the metalloprotein binder and/or modified cleavase. In some embodiments, the method provided herein comprises binding metalloprotein binder-coding tag conjugates to a modified N-terminal amino acid residue of an immobilized peptide associated with a recording tag, transferring identifying information from the coding tag to the recording tag using a ligation or primer extension, and cleaving the modified N-terminal amino acid residue. The method and metalloprotein binders provided herein are useful for de novo peptide identification or sequencing.

Immunogenic compositions comprising one or more polypeptides, wherein the one or more polypeptides: is capable of binding to Major Histocompatibility Complex (MHC) class I, and is derived from one or more proteins of SARS-CoV-2. Also provided include methods of treating and preventing diseases using the immunogenic compositions.