The present invention relates to protein sequencing, more particularly the invention discloses improved aminopeptidases for single molecule protein sequencing and/or amino acid identification. Said aminopeptidases can enzymatically cleave off N-terminal amino acids and are highly suitable in a kinetics-based peptide sequencing approach. Based on the kinetics of the cleaving reaction or of the engagement between said aminopeptidases and peptide to be sequenced, information on the identity of the cleaved amino acids is provided.

This disclosure relates to new methods for antibody characterization sequencing, such as middle down antibody characterization and sequencing, for example, for de novo antibody sequencing, identifying known antibodies in a sample, or verifying the sequence of antibodies in a sample. In some embodiments, the methods involve exposing antibodies to cathepsin D, cathepsin L, and/or cathepsin D and L, followed by mass spectrometry and sequence identification and deconvolution.

The present disclosure relates to methods and kits for performing an identification of a terminal amino acid residue of the polypeptide, or performing a polypeptide sequencing. The methods include a step of contacting the terminal amino acid residue of the polypeptide with a coupler, followed by attaching the coupler-polypeptide complex to the solid support and cleaving the coupler-polypeptide complex from the polypeptide, thereby isolating the terminal amino acid residue of the polypeptide from the remaining amino acid residues of the polypeptide in complex with the coupler, thereby enabling efficient identification of the terminal amino acid residue via recognition by binding agents capable of binding to the coupler-amino acid complex. In some embodiments, the coupler and the polypeptide are both associated with stabilizing components, and after binding of the coupler to the terminal amino acid of the polypeptide, tethering complex is formed between the stabilizing components releasably attached to the solid support.

The present invention relates to the field of biochemistry, more particularly to proteomics, more particularly to protein sequencing, even more particularly to single molecule peptide sequencing. The invention discloses means and methods for single molecule protein sequencing and/or amino acid identification using cleavage inducing agent. Said cleavage inducing agents which are not specific for one particular amino acid, cleave polypeptides step by step from the N-terminus onwards and provide information on the identity of the cleaved amino acids based on the kinetics of said reaction.

Techniques for multi-dimensional signal analysis are described herein. The techniques may be used in one or more sequencing applications. For example, according to some aspects, there is provided a method comprising: determining information about a sample that emits emission light in response to excitation light based on at least one of pulse duration and interpulse duration and at least two of wavelength, intensity, and lifetime of the emission light, wherein the sample comprises a reagent configured to be coupled to a luminescent label, and wherein a shielding element is disposed between the reagent and the luminescent label.

The present disclosure provides methods of identifying and quantifying the peptides displayed by the major histocompatibility complex (MHC). Such methods may comprise the ability to determine the type, identity, and quantity of each peptide displayed by the MHC. In some embodiments, these methods may be used to develop an anti-cancer therapy or type the HLA of a patient. Also provided herein are compositions comprising peptides from the MHC which have been prepared for sequencing.

The present invention relates to the field of biochemistry, more particularly to proteomics, more particularly to protein sequencing, even more particularly to single molecule peptide sequencing. The invention discloses methods for single molecule protein sequencing and/or amino acid identification using cleavage inducing agents which are not specific for one particular amino acid, cleave polypeptides step by step from the N-terminus onwards and provide information on the identity of the cleaved amino acids based on the reaction kinetics.

The present invention generally pertains to methods of determining the amino acid sequence of a protein. In particular, the present invention pertains to the use of position-selective dimethylation and liquid chromatography-mass spectrometry to enhance the signal of N-terminal peptides and shift the signal of N-terminal peptides and corresponding b ions, thus facilitating a determination of the sequence of N-terminal peptides.

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 comprising 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.

The present invention relates to the field of identifying proteins and peptides, and more specifically large-scale sequencing of single peptides in a mixture of diverse peptides at the single molecule level. The present invention also relates to methods for identifying amino acids in peptides, including peptides comprising unnatural amino acids. In one embodiment, the present invention contemplates labeling the N-terminal amino acid with a first label and labeling an internal amino acid 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.