16 results about "Peptide sequencing" patented technology

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.

The application provides a bidirectional peptide sequencing method based on a self-attention mechanism and application, and comprises the following steps: obtaining mass spectrum raw data, processing the mass spectrum raw data to obtain peptide features and secondary fragment ion spectra associated with the peptide features; inputting the peptide features and the secondary fragment ion spectra into a bidirectional independent sequencing model in a bidirectional peptide sequencing model to output bidirectional independent predicted candidate sequences, inputting the peptide features and the secondary fragment ion spectra into a bidirectional interaction sequencing model in the bidirectional peptide sequencing model to output bidirectional interaction predicted candidate sequences, and taking a union of the bidirectional independent predicted candidate sequences and the bidirectional interaction predicted candidate sequences as final candidate sequences; inputting the final candidate sequences into the bidirectional independent sequencing model again to score, and selecting a peptide sequence with the highest score as a prediction result, thereby achieving an effect that peptide sequence inference can be performed directly from accurate mass of secondary spectra and primary spectra generated in experiments without a database, and new peptide protein discovery is facilitated.

The disclosure provides a nanopore system assembled with non-membrane proteins for detecting analytes. Also disclosed are the methods, kits, and detection devices employing the disclosed nanopore system. The nanopore system has a wide variety of applications, including single molecule detection, DNA / RNA / peptide sequencing, sensing of chemicals, biological reagents, and polymers, and disease diagnosis.

The present disclosure provides reagents and methods useful for single-molecule sequencing of proteins through use of a sequencing reagent of Formula I, IV, IV', IV", IV-A, IV-B, or V-C. The reagents and methods described herein provide for high-throughput single molecule and high efficiency protein and peptide sequencing in mild conditions allowing for high resolution investigation of complex biological systems.

The present disclosure provides methods and systems of multiplexed polypeptide sequencing using barcodes. In some embodiments, each barcode comprises at least a barcode moiety, wherein the barcode moiety comprises (i) a codon capable of being recognized and distinguished by a nanopore device having a nanopore sensor, and (ii) a time-control element capable of temporarily holding the codon at the nanopore sensor.

This invention discloses a mulberry leaf antihypertensive active peptide, its preparation method, and its application. Using mulberry leaves as raw material, this invention prepares mulberry leaf albumin. Enzymatic hydrolysis parameters, including hydrolysis time, pH, enzyme-to-substrate ratio, and substrate concentration, were optimized through single-factor and orthogonal experiments, providing optimal hydrolysis conditions for preparing crude ACE-inhibiting peptides. Further purification, peptide sequencing, and virtual screening identified highly active ACE-inhibiting peptides with strong solubility and good ACE-inhibiting activity. The two peptides with the highest activity, VPSCFDLTGK and RLPDFHGL, showed the highest IC50 values. 50 The values ​​were 8.23 ​​μmol / L (8.765 μg / mL) and 23.01 μmol / L (23.58 μg / mL), respectively. These bioactive peptides can act as angiotensin-converting enzyme inhibitory peptides, thereby lowering blood pressure by inhibiting ACE activity.

Provided are a binary complex containing a chaperone molecule and the use thereof in polypeptide sequencing. The binary complex comprises a chaperone molecule and a polypeptide to be detected that are covalently linked, wherein the chaperone molecule is selected from any one or more of the following: PEG, a spacer, a deoxyribose phosphate, a ribose phosphate, a nucleotide, a deoxynucleotide, a peptide nucleic acid or a locked nucleotide; the number of constituent units of the chaperone molecule is ≥1; and the number of amino acids of said polypeptide is ≥2. The above development and use are conducive to improving the resolution of nanopore polypeptide sequencing, and are of great significance for the advancement of nanopore polypeptide sequencing technology.

Provided are a polypeptide sequencing data screening method, a neural network model training method, and a related device, relating to the technical field of biotechnology. The polypeptide sequencing data screening method comprises: acquiring a plurality of pieces of original polypeptide sequencing data, wherein the original polypeptide sequencing data is obtained by means of nanopore sequencing technology; performing feature extraction on the plurality of pieces of original polypeptide sequencing data on the basis of a preset neural network model, to obtain a plurality of depth features, wherein the neural network model is a model obtained by training on the basis of preset sample data, and the preset sample data comprises a plurality of pieces of sample polypeptide sequencing data and classification labels corresponding thereto; performing point cloud density estimation on the plurality of depth features, to obtain a point cloud density estimation value corresponding to each depth feature; and performing screening on the original polypeptide sequencing data on the basis of the point cloud density estimation value, to obtain a screening result. Provided embodiments can reduce noise data of a polypeptide sequence and improve the quality of the polypeptide sequence.

The invention provides a nucleic acid polypeptide compound and application thereof in peptide sequencing. The nucleic acid polypeptide compound comprises a first nucleic acid fragment, polypeptide to be detected and a compound nucleic acid fragment which are connected in sequence; wherein the composite nucleic acid fragment comprises a nucleic acid sequence capable of forming a hairpin structure, after the hairpin structure is formed, the composite nucleic acid fragment comprises double-chain nucleic acid and single-chain nucleic acid, one end of the single-chain nucleic acid is connected with the double-chain nucleic acid, and the other end of the single-chain nucleic acid is connected with the polypeptide to be detected. The nucleic acid sequence guides polypeptides with different charges to pass through the nanopore, so that any polypeptide sequence can be detected.

This invention discloses a nanopore peptide sequencing method based on host-guest interactions. The method includes the following steps: 1) sequentially hydrolyzing the peptide to be sequenced into monomeric amino acids using a proteolytic enzyme; 2) linking the monomeric amino acids to a load molecule containing the guest molecule structure; 3) performing single-channel recording in a nanopore after the host molecule and guest molecule have bound. This invention provides a de novo sequencing method that utilizes the sequential hydrolysis of peptides by exopeptidases to obtain the peptide sequence information; by linking the load molecule to a single amino acid, the current blocking ratio of the characteristic signals generated after the binding of 20 encoding amino acids to the load molecule is accurately measured. The characteristic current is contributed by a single amino acid, eliminating decoding difficulties; the target peptide dosage is small, and the detection limit is low; the experimental operation is safe and simple, with most reactions carried out in an aqueous phase, without involving toxic reagents, making it green and safe.

The present disclosure provides reagents and methods useful for single-molecule sequencing of proteins through use of a sequencing reagents of Formula (Ia), (Ib), (I-Aa), (I-Ab), (IIa), (IIb), (II-Aa), (II-Ab), (IIIa), (IIIb), (III-Aa), (III-Ab), (IVa), (IVb), (IV-Aa), (IV-Ab), (IV-Ba), (IV-Bb), (V), (V-A), (V-B), (VI), (VI-A), (VII), or (VII-A). The reagents and methods described herein provide for high-throughput and high efficiency protein and peptide sequencing in mild conditions allowing for high resolution investigation of complex biological systems.

Methods of identifying a sequence of a polypeptide within a heterogenous mixture of polypeptides, the polypeptide being immobilized to a support and having at least one labeled amino acid residue. Methods involve detecting at least one signal or signal change from the immobilized polypeptide and subjecting the polypeptide to conditions sufficient to remove at least one amino acid residue from the polypeptide.

Peptide sequencing is important in decoding data stored in data-encoding peptides. Tandem mass spectrometry (MS / MS) is particularly useful for peptide sequencing. In a computer-implemented method for sequencing a data-encoding peptide from an experimental spectrum, raw data of the experimental spectrum is first pre-processed to remove uninterpretable peaks, resulting in pre-processed data. A first set of one or more candidate sequences of a peptide sequence that competes with the peptide is identified from the spectrum. The spectrum is formed from the pre-processed data rather than the raw data to result in a smaller number of candidate sequences, thereby reducing the time cost of sequencing. The first set of candidate sequences is then processed to estimate the peptide sequence, resulting in a set of peptide sequence estimate sequences. Each estimate sequence is verified for invalidity. The set of peptide sequence estimate sequences is cleaned to remove any invalid estimate sequences.

The application discloses a training method and device of a new antigen short peptide immunogenicity sequencing model and a storage medium, and relates to the technical field of biological information. The training method comprises the following steps: (1) extracting features in real immunogenicity data, containing: short mutant polypeptide sequences, and corresponding gene expression, RNA mutation frequency, mutation harmfulness, mutation polypeptide-MHCI binding, mutation polypeptide-MHCI binding stability, mutation polypeptide-wild polypeptide binding difference, and mutation polypeptide-wild polypeptide binding stability difference; (2) performing data normalization based on the features obtained in step (1) to obtain normalized feature values; and (3) taking a machine learning model as a basic model, inputting the normalized feature values to perform training, and obtaining a new antigen short peptide sequencing model.

The present disclosure provides reagents and methods useful for single-molecule sequencing of proteins through use of a sequencing reagent of Formula I, IV, IV′, IV″, IV-A, IV-B, or V-C. The reagents and methods described herein provide for high-throughput single molecule and high efficiency protein and peptide sequencing in mild conditions allowing for high resolution investigation of complex biological systems.

The present description provides methods, assays and reagents useful for sequencing proteins. Sequencing proteins in a broad sense involves observing the plausible identity and order of amino acids, which is useful for sequencing single polypeptide molecules or multiple molecules of a single polypeptide. In one aspect, the methods are useful for sequencing multiple polypeptides. The methods and reagents described herein can be useful for high resolution interrogation of the proteome and enabling ultrasensitive diagnostics critical for early detection of diseases.