Use of a limited digestion with a proteolytic enzyme of a multispecific antibody for the analysis of the multispecific antibody's light chain pairing.

Methods and system for identifying and quantifying antibody fragments and identifying the site of fragmentation on an antibody are provided herein.

The present invention generally pertains to methods of preventing disulfide scrambling in non-reducing liquid chromatography-mass spectrometry analysis of a protein of interest. In particular, the present invention pertains to the addition of cystamine to a non-reducing liquid chromatography-mass spectrometry analysis of an antibody to prevent disulfide scrambling.

The application provides a method of identifying or monitoring a plasma cell associated disease, comprising purifying immunoglobulin free light chains (FLCs) from a sample from a subject with anti-FLC specific antibodies or fragments thereof and subjecting the purified sample to a mass spectrometry technique to identify the presence of one or more peaks corresponding to one or more monoclonal FLCs in the sample.

Liquid chromatography-free methods for quantitating a target protein in a sample are provided. One embodiment provides a liquid chromatography-free method for quantifying target antibodies in a sample including the steps of spiking the sample with a labeled internal standard antibody, digesting the antibodies in the sample to produce peptides, fractionating the peptides; and quantifying the target antibodies using a direct infusion MS.sup.2 system containing one or more ion traps and two or more quadrupole mass filters and an electrospray ionizer, wherein the method is liquid chromatography-free.

This document relates to methods for detecting and quantifying heavy and light chains of immunoglobulin using mass spectrometry techniques.

Some embodiments disclosed herein provide a plurality of compositions each comprising a protein binding reagent conjugated with an oligonucleotide. The oligonucleotide comprises a unique identifier for the protein binding reagent it is conjugated with, and the protein binding reagent is capable of specifically binding to a protein target. Further disclosed are methods and kits for quantitative analysis of a plurality of protein targets in a sample and for simultaneous quantitative analysis of protein and nucleic acid targets in a sample. Also disclosed herein are systems and methods for preparing a labeled biomolecule reagent, including a labeled biomolecule agent comprising a protein binding reagent conjugated with an oligonucleotide.

Herein is reported a method for determining the epitope of an antibody specifically binding to a therapeutic antibody comprising the steps of a) incubating a sample, which comprises serum and the antibody specifically binding to a therapeutic antibody, separately with i) at least a Fab fragment of the therapeutic antibody, and ii) at least a Fab fragments of the therapeutic antibody in which the HVRs forming a paratope have been replaced with germline sequences, and detecting the binding or non-binding of the antibody specifically binding to a therapeutic antibody to the at least a Fab fragment in any of i) to ii), and b) determining the epitope of the antibody specifically binding to a therapeutic antibody to be in the at least one HVR that has been replaced in ii) if binding is detected in i) and non-binding is detected in ii).

The present disclosure disclosed herein a recombinant antibody or the antigen-binding fragment thereof which specifically binds GM2-activator protein (GM2AP). The recombinant antibody or the antigen-binding fragment thereof comprises a light chain variable region (LCVR) comprising three light chain complementary determining regions (LCDR1-3) amino acid sequences and a heavy chain variable region (HCVR) comprising three heavy chain complementary determining regions (HCDR1-3) set forth in the sequences disclosed in the embodiments of the present application. Polynucleotides encoding the same, vectors, host cells, kits and methods for detecting GM2AP and methods for inducing these recombinant antibodies or the antigen-binding fragment thereof are also provided.

The disclosure is directed to conjugates, e.g. PNA conjugates, as well as methods of employing the conjugates for detecting one or more targets in a biological sample, e.g. a tissue sample.