The present invention relates to methods of cleaving the N-terminal amino acid from a polypeptide, which may be in free form or conjugated to a carrier or surface, such as a bead. It provides methods to activate the N-terminal amine of a polypeptide to promote formation of a cyclic adduct of the N-terminal amino acid, resulting in cleavage of the N-terminal amino acid from the polypeptide. The method can be used to sequence and/or analyze a polypeptide. For example, the methods can be combined with methods described herein for sequencing and/or analysis that employ barcoding and nucleic acid encoding of molecular recognition events, and/or detectable labels. The invention also provides compounds and kits useful for practicing these methods.

Methods and compositions using artificial antigen presenting cells in immunotherapy. The artificial antigen presenting cells comprise substrate particles bound to endogenous MHC-peptide complexes obtained from one or more cells. Methods include administering the artificial antigen presenting cells to a patient to activate antigen-specific T cells.

An object of the present invention is to provide a polypeptide having a high binding capacity for an immunoglobulin kappa chain, and having excellent alkali stability, by modifying an amino acid sequence of an immunoglobulin-binding domain of Protein L derived from Peptostreptococcus magnus. A polypeptide having a high binding capacity for an immunoglobulin kappa chain, and having excellent alkali stability can be obtained by substituting specific lysine residues in an immunoglobulin-binding domain of Protein L derived from Peptostreptococcus magnus 3316 strain, with a basic amino acid or a hydroxyl group-containing amino acid.

An object of the present invention is to provide a polypeptide having a high binding capacity for an immunoglobulin kappa chain, and having excellent alkali stability, by modifying an amino acid sequence of an immunoglobulin-binding domain of Protein L derived from Peptostreptococcus magnus. A polypeptide having a high binding capacity for an immunoglobulin kappa chain, and having excellent alkali stability can be obtained by substituting specific lysine residues in an immunoglobulin-binding domain of Protein L derived from Peptostreptococcus magnus 3316 strain, with a basic amino acid or a hydroxyl group-containing amino acid.

A polypeptide contains laminin beta-4 and a carrier contains the polypeptide. An antibody, preferably autoantibody, is against laminin beta-4. Furthermore, use of the polypeptide, carrier or autoantibody for the diagnosis of a disease, and a method with the step of detecting an autoantibody against laminin beta-4 in a sample are described.

A polypeptide contains laminin beta-4 and a carrier contains the polypeptide. An antibody, preferably autoantibody, is against laminin beta-4. Furthermore, use of the polypeptide, carrier or autoantibody for the diagnosis of a disease, and a method with the step of detecting an autoantibody against laminin beta-4 in a sample are described.

The present invention provides for engineered molecular opsonins that may be used to bind biological pathogens or identify subclasses or specific pathogen species for use in devices and systems for treatment and diagnosis of patients with infectious diseases, blood-borne infections or sepsis. An aspect of the invention provides for mannose-binding lectin (MBL), which is an abundant natural serum protein that is part of the innate immune system. The ability of this protein lectin to bind to surface molecules on virtually all classes of biopathogens (viruses, bacteria, fungi, protozoans) make engineered forms of MBL extremely useful in diagnosing and treating infectious diseases and sepsis.

The present invention provides for engineered molecular opsonins that may be used to bind biological pathogens or identify subclasses or specific pathogen species for use in devices and systems for treatment and diagnosis of patients with infectious diseases, blood-borne infections or sepsis. An aspect of the invention provides for mannose-binding lectin (MBL), which is an abundant natural serum protein that is part of the innate immune system. The ability of this protein lectin to bind to surface molecules on virtually all classes of biopathogens (viruses, bacteria, fungi, protozoans) make engineered forms of MBL extremely useful in diagnosing and treating infectious diseases and sepsis.

The present invention provides a method for simply isolating exosomes from a sample containing exosomes. The present invention includes a complex forming step of forming a complex by binding an exosome in a sample to a particular peptide that contains lysines and is supported on a carrier and a dissociating step of dissociating the exosome from the complex by bringing the complex into contact with a dissociation buffer containing metal cations.

The present disclosure provides for compositions and methods for identifying peptide classifiers. In one embodiment, a peptide classifier for diagnosing rheumatoid arthritis includes a composition comprising a plurality of molecules. Each molecule comprises a peptide having a sequence selected from SEQ ID NOS: 1-8861, wherein the plurality of molecules defines a classifier for rheumatoid arthritis.