HLA class II histocompatibility antigen, DRB1-3 chain (HLA-DRB1),partial, human, recombinant

Organism: Homo sapiens (Human). Source: E.coli. Expression Region: 31-266aa. Protein Length: Partial. Tag Info: N-terminal 6xHis-tagged. Target Protein Sequence: DTRPRFLEYS TSECHFFNGT ERVRYLDRYF HNQEENVRFD SDVGEFRAVT ELGRPDAEYW NSQKDLLEQK RGRVDNYCRH NYGVVESFTV QRRVHPKVTV YPSKTQPLQH HNLLVCSVSG FYPGSIEVRW FRNGQEEKTG VVSTGLIHNG DWTFQTLVML ETVPRSGEVY TCQVEHPSVT SPLTVEWRAR SESAQSKMLS GVGGFVLGLL FLGAGLFIYF RNQKGHSGLQ PRGFLS. Purity: Greater than 90% as determined by SDS-PAGE. Endotoxin: Not test. Biological Activity: n/a. Form: Liquid or Lyophilized powder. Buffer: If the delivery form is liquid, the default storage buffer is Tris/PBS-based buffer, 5%-50% glycerol. If the delivery form is lyophilized powder, the buffer before lyophilization is Tris/PBS-based buffer, 6% Trehalose, pH 8.0. Reconstitution: We recommend that this vial be briefly centrifuged prior to opening to bring the contents to the bottom. Please reconstitute protein in deionized sterile water to a concentration of 0.1-1.0 mg/mL.We recommend to add 5-50% of glycerol (final concentration) and aliquot for long-term storage at -20 °C/-80 °C. Our default final concentration of glycerol is 50%. Customers could use it as reference. Storage: The shelf life is related to many factors, storage state, buffer ingredients, storage temperature and the stability of the protein itself. Generally, the shelf life of liquid form is 6 months at -20 °C/-80 °C. The shelf life of lyophilized form is 12 months at -20 °C/-80 °C. Notes: Repeated freezing and thawing is not recommended. Store working aliquots at 4 °C for up to one week. Relevance: A beta chain of antigen-presenting major histocompatibility complex class II (MHCII) molecule. In complex with the alpha chain HLA-DRA, displays antigenic peptides on professional antigen presenting cells (APCs) for recognition by alpha-beta T cell receptor (TCR) on HLA-DRB1-restricted CD4-positive T cells. This guides antigen-specific T helper effector functions, both antibody-mediated immune response and macrophage activation, to ultimately eliminate the infectious agents and transformed cells (PubMed:29884618, PubMed:22327072, PubMed:27591323, PubMed:8642306, PubMed:15265931, PubMed:31495665). Typically presents extracellular peptide antigens of 10 to 30 amino acids that arise from proteolysis of endocytosed antigens in lysosomes (PubMed:8145819). In the tumor microenvironment, presents antigenic peptides that are primarily generated in tumor-resident APCs likely via phagocytosis of apoptotic tumor cells or macropinocytosis of secreted tumor proteins (PubMed:31495665). The selection of the immunodominant epitopes follows two processing modes: 'bind first, cut/trim later' for pathogen-derived antigenic peptides and 'cut first, bind later' for autoantigens/self-peptides (PubMed:25413013). The anchor residue at position 1 of the peptide N-terminus, usually a large hydrophobic residue, is essential for high affinity interaction with MHCII molecules (PubMed:8145819). Reference: "CD4+ T cell-mediated HLA class II cross-restriction in HIV controllers." Galperin M., Farenc C., Mukhopadhyay M., Jayasinghe D., Decroos A., Benati D., Tan L.L., Ciacchi L., Reid H.H., Rossjohn J., Chakrabarti L.A., Gras S. Sci. Immunol. 3:0-0(2018). Function: nan