Nautilus Subsidiary, Inc.

A method for characterizing proteins, including steps of (a) detecting a plurality of proteins, wherein individual proteins of the plurality are associated with unique identifiers, wherein the detecting distinguishes the identities of the individual proteins and the unique identifiers associated with the individual proteins; (b) digesting the proteins to form peptides, wherein the peptides from each protein are associated with the unique identifiers for the respective individual protein; (c) detecting the peptides and associated unique identifiers, wherein the detecting distinguishes characteristics of individual peptides, and wherein the detecting distinguishes unique identifiers associated with the individual peptides; and (d) correlating characteristics detected in step (c) with individual proteins detected in step (a) based on the unique identifiers associated with the individual proteins and the peptides.

Methods, systems, and compositions are provided for characterizing the interactions of binding reagents with ligand-binding proteins, such as enzymes. Unknown ligand-binding proteins may be identified at single-molecule resolution based upon their interactions with binding reagents. Proteins with unknown ligand-binding behaviors may be characterized by binding reagent methods set forth herein.

Compositions, systems, and methods for the display of analytes such as biomolecules are described. Display of analytes is achieved by coupling of the analytes to displaying molecules that are configured to associate with surfaces or interfaces. Arrays of analytes may be formed from the described systems for utilization in assays and other methods.

Methods and systems are provided for accurate and efficient identification and quantification of proteins. In an aspect, disclosed herein is a method for identifying a protein in a sample of unknown proteins, comprising receiving information of a plurality of empirical measurements performed on the unknown proteins; comparing the information of empirical measurements against a database comprising a plurality of protein sequences, each protein sequence corresponding to a candidate protein among a plurality of candidate proteins; and for each of one or more of the plurality of candidate proteins, generating a probability that the candidate protein generates the information of empirical measurements, a probability that the plurality of empirical measurements is not observed given that the candidate protein is present in the sample, or a probability that the candidate protein is present in the sample; based on the comparison of the information of empirical measurements against the database.

A method of identifying extant proteins, including (a) inputting to a computer processor: (i) a plurality of empirical binding profiles, individual empirical binding profiles including empirical binding outcomes for binding of an extant protein to a plurality of different affinity reagents, (ii) a plurality of candidate outcome profiles, individual candidate outcome profiles including binding outcomes for binding of a candidate protein to the plurality of different affinity reagents, and (iii) a plurality of pseudo outcome profiles, individual pseudo outcome profiles including a rearrangement of a candidate outcome profile; (b) performing a process in the computer processor to identify extant proteins based on the empirical binding profiles of the extant proteins and the plurality of candidate outcome profiles; and (c) performing a process in the computer processor to determine a false discovery statistic for the extant proteins based on the plurality of pseudo outcome profiles.

The present disclosure provides a method of identifying a polypeptide. The method can include steps of (a) attaching a polypeptide to a particle or solid support, thereby producing an immobilized polypeptide having a plurality of amino acids linked to the particle or solid support; (b) fragmenting the immobilized polypeptide, whereby the particle is attached to a set of fragments of the polypeptide; (c) performing a binding assay including contacting the set of fragments with a plurality of affinity reagents and detecting binding of affinity reagents of the plurality of affinity reagents to the set of fragments; and (d) identifying the polypeptide from results of the binding assay

Systems for identifying a protein within a sample are provided herein. A panel of antibodies are acquired, none of which are specific for a single protein or family of proteins. Additionally, the binding properties of the antibodies in the panel are determined. Further, the protein is iteratively exposed to a panel of antibodies. Additionally, a set of antibodies which bind the protein are determined. The identity of the protein is determined using one or more deconvolution methods based on the known binding properties of the antibodies to match the set of antibodies to a sequence of a protein.

The methods described herein provide a means of producing an array of spatially separated proteins. The method relies on covalently attaching each protein of the plurality of proteins to a structured nucleic acid particle (SNAP), and attaching the SNAPs to a solid support.

Provided herein are methods, compositions and apparatus useful for individually manipulating and individually detecting analytes such as proteins. Analytes can be attached to particles to facilitate individual manipulation or detection of the particle-attached analytes. The particle-attached analytes can be composed of a single analyte attached to a single particle, such that no more than one analyte is attached per particle and no more than one particle is attached per analyte.

Methods and systems are provided herein for selecting an affinity reagent which binds a desired peptide epitope in a plurality of sequence contexts. The method relies on obtaining a peptide library, each peptide having the sequence αXβ, wherein X is the desired peptide epitope, wherein each of α and β comprise an amino acid, using the peptide library to select an affinity reagent.