{"product_id":"recombinant-human-b-lymphocyte-antigen-cd19-cd19-partial-active-bhp10506933","title":"Recombinant Human B-lymphocyte antigen CD19 (CD19), partial (Active)","description":"\u003ch2\u003eOverview\u003c\/h2\u003e\u003cp\u003eThis Recombinant Protein provides recombinant \u003cstrong\u003eCD19\u003c\/strong\u003e from Homo sapiens (Human), produced in Mammalian cell (region 20-291aa). It is commonly used as a defined reagent for assay development, binding studies, and mechanistic research (RUO).\u003c\/p\u003e\u003ch2\u003eKey elements and design rationale\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eRegion:\u003c\/strong\u003e 20-291aa (domain boundaries can affect binding\/activity readouts).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExpression host:\u003c\/strong\u003e Mammalian cell (may differ from native PTMs\/processing).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTag(s):\u003c\/strong\u003e Fc (supports purification\/detection; consider tag effects in controls).\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eBiological background\u003c\/h2\u003e\u003cp\u003eAlso reported as B-Lymphocyte Antigen CD19; B-Lymphocyte Surface Antigen B4; Differentiation Antigen CD19; T-Cell Surface Antigen Leu-12; CD19. Assembles with the antigen receptor of B-lymphocytes in order to decrease the threshold for antigen receptor-dependent stimulation.\u003c\/p\u003e\u003ch2\u003eResearch relevance and current trends\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eQuantitative mapping of ligand\/receptor signaling to downstream phospho- and transcriptional programs.\u003c\/li\u003e\n\u003cli\u003eActivity assay development for kinetics, substrate scope, and inhibitor\/activator profiling.\u003c\/li\u003e\n\u003cli\u003eUse of recombinant standards to improve assay calibration and cross-study comparability.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eCD19 is a single-pass type I membrane protein containing 2 Ig-like C2-type (immunoglobulin-like) domains. CD19 is expressed on follicular dendritic cells and B cells. In fact, it is present on B cells from earliest recognizable B-lineage cells during development to B-cell blasts but is lost on maturation to plasma cells. CD19 primarily acts as a B cell co-receptor in conjunction with CD21 and CD81. Upon activation, the cytoplasmic tail of CD19 becomes phosphorylated, which leads to binding by Src-family kinases and recruitment of PI-3 kinase. CD19 Assembles with the antigen receptor of B lymphocytes in order to decrease the threshold for antigen receptor-dependent stimulation. Defects in CD19 are the cause of immunodeficiency common variable type 3 (CVID3) which is a primary immunodeficiency characterized by antibody deficiency, hypogammaglobulinemia, recurrent bacterial infections and an inability to mount an antibody response to antigen.\u003c\/p\u003e\u003ch2\u003eCommon research applications\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eStandard curve or spike-in reference for quantitative assays involving CD19\u003c\/li\u003e\n\u003cli\u003eBinding interaction studies (e.g., SPR\/BLI or plate-based binding formats)\u003c\/li\u003e\n\u003cli\u003eCell-based stimulation studies with downstream marker readouts (conceptual)\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eNotes for experimental interpretation\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eRecombinant constructs may not capture all native isoforms or PTMs.\u003c\/li\u003e\n\u003cli\u003eConsider tag- or host-related effects when interpreting binding or activity.\u003c\/li\u003e\n\u003cli\u003eUse appropriate blanks and matrix\/control concepts to separate signal from background.\u003c\/li\u003e\n\u003c\/ul\u003e\u003c!-- Sources (internal): - UniProtKB P15391 — UniProt — https:\/\/www.uniprot.org\/uniprotkb\/P15391 - NCBI Gene search: CD19 — NCBI — https:\/\/www.ncbi.nlm.nih.gov\/gene\/?term=CD19 - Ensembl search: CD19 — Ensembl — https:\/\/www.ensembl.org\/Multi\/Search\/Results?q=CD19 - Reactome Pathway Browser — Reactome — https:\/\/reactome.org\/ - NCBI Bookshelf — NCBI — https:\/\/www.ncbi.nlm.nih.gov\/books\/ --\u003e","brand":"CUSABIO TECHNOLOGY LLC","offers":[{"title":"1 mg","offer_id":53053397860717,"sku":"CSB-AP005061HU-1MG","price":4254.0,"currency_code":"USD","in_stock":true},{"title":"500 ug","offer_id":53053516218733,"sku":"CSB-AP005061HU-500UG","price":2978.0,"currency_code":"USD","in_stock":true},{"title":"50 ug","offer_id":53053516251501,"sku":"CSB-AP005061HU-50UG","price":610.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0949\/7424\/7277\/files\/CSB-AP005061HU.jpg?v=1772177618","url":"https:\/\/www.ebiohippo.com\/products\/recombinant-human-b-lymphocyte-antigen-cd19-cd19-partial-active-bhp10506933","provider":"BioHippo","version":"1.0","type":"link"}