The present disclosure provides a detection device capable of detecting a low concentration of an analyte with high sensitivity. The detection apparatus according to the present disclosure comprises a metal microstructure on which a first VHH antibody having a property of binding specifically to the analyte is immobilized and which generate surface plasmon by being irradiated with excitation light, an inlet through which a second VHH antibody and a sample that may contain an analyte are introduced, wherein the second VHH antibody has a property of binding specifically to the analyte and is labeled with a fluorescent substance, a light source for irradiating the metal microstructure to which the second VHH antibody and the sample have been introduced with the excitation light, and a detection unit for detecting the analyte on the basis of fluorescence generated from the fluorescent substance by the irradiation of the excitation light.

Recombinant poly-IgA oligomers that form high-order oligomers resembling poly-IgA of IgA nephropathy are provided. Injection of recombinant IgA oligomers in an animal model produces prominent renal glomerular mesangial deposition of recombinant poly IgA oligomer, as in IgA nephropathy patients. Thus, producing a model of IgAN pathology that is able to provide screening and evaluation of therapeutic drugs and diagnostic tests.

The present disclosure provides a rapid, scalable, and high-throughput method of identifying the precise regions in a receptor protein which are involved in binding of a molecule of interest. The method of the instant disclosure is useful where the crystal structure of a protein of interest is not available. Also provided are surface display libraries, and methods of making the same.

Provided are methods for quantitating an amount of a polypeptide that comprises a portion of an antibody present in a sample (e.g., a plasma or serum sample) wherein the antibody comprises a constant region (e.g., a heavy chain or light chain constant region) that comprises an engineered mutation.

Described herein are methods, assays and techniques for detecting and/or measuring anti-drug antibodies that bind to a protein, polypeptide or other compound or molecule that comprises at least one immunoglobulin variable domain with an exposed C-terminal region.

Provided herein are methods for identifying new biomarkers for various diseases using proteomics, peptidomics, metabolics, proteoglycomics, glvcomics, mass spectrometry and machine learning. The present disclosure also provides glycopeptides as biomarkers for various diseases such as cancer and autoimmune diseases.

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.

An antibody fragment includes only constant regions of an antibody having no variable regions of an antibody is disclosed. The antibody fragment (IgCw-γ1ε.sub.2-4/κ) contains heavy chain and light-chain constant regions in which a gamma constant region ((Cγ1) and an epsilon constant region (Cε.sub.2-4) are fused; a nucleic acid encoding the antibody fragment; a kit including the antibody or nucleic acid; and use thereof. The recombinant protein IgCw-γ1ε.sub.2-4/κ containing only of the constant regions of an antibody can be used as an Fc epsilon receptor inhibitor for inhibiting allergic responses. Therefore, IgCw-γ.sub.1ε.sub.2-4/κ can be used in various ways in the biomedical science field.

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 present invention relates to the field of GPCR structure biology and signaling. In particular, the present invention relates to protein binding domains directed against or capable of specifically binding to a functional conformational state of a G-protein-coupled receptor (GPCR). More specifically, the present invention provides protein binding domains that are capable of increasing the stability of a functional conformational state of a GPCR, in particular, increasing the stability of a GPCR in its active conformational state. The protein binding domains of the present invention can be used as a tool for the structural and functional characterization of G-protein-coupled receptors bound to various natural and synthetic ligands, as well as for screening and drug discovery efforts targeting GPCRs. Moreover, the invention also encompasses the diagnostic, prognostic and therapeutic usefulness of these protein binding domains for GPCR-related diseases.