{"product_id":"recombinant-human-cd81-antigen-cd81-partial-bhp10507698","title":"Recombinant Human CD81 antigen (CD81), partial","description":"\u003ch2\u003eOverview\u003c\/h2\u003e\u003cp\u003eThis Recombinant Protein provides recombinant \u003cstrong\u003eCD81\u003c\/strong\u003e from Homo sapiens (Human), produced in Mammalian cell (region 113-201aa). 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 113-201aa (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 hFc1-tag (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 26 kDa cell surface protein TAPA-1 (Target of the antiproliferative antibody 1) (Tetraspanin-28) (Tspan-28) (CD_antigen: CD81) (TAPA1) (TSPAN28). Structural component of specialized membrane microdomains known as tetraspanin-enriched microdomains, which act as platforms for receptor clustering and signaling. Essential for trafficking and compartmentalization of CD19 receptor on the surface of activated B cells. Upon initial encounter with microbial pathogens, enables the assembly of CD19-CR2\/CD21 and B cell receptor (BCR) complexes at signaling TERMs, lowering the threshold dose of antigen required to trigger B cell clonal expansion and antibody production. In T cells, facilitates the localization of CD247\/CD3 zeta at antigen-induced synapses with B cells, providing for costimulation and polarization toward T helper type 2 phenotype. Present in MHC class II compartments, may also play a role in antigen presentation. Can act both as positive and negative regulator of homotypic or heterotypic cell-cell fusion processes. Positively regulates sperm-egg fusion and may be involved in acrosome reaction. In myoblasts, associates with CD9 and PTGFRN and inhibits myotube fusion during muscle regeneration. In macrophages, associates with CD9 and beta-1 and beta-2 integrins, and prevents macrophage fusion into multinucleated giant cells specialized in ingesting complement-opsonized large particles. Also prevents the fusion of mononuclear cell progenitors into osteoclasts in charge of bone resorption. May regulate the compartmentalization of enzymatic activities. In T cells, defines the subcellular localization of dNTPase SAMHD1 and permits its degradation by the proteasome, thereby controlling intracellular dNTP levels. Also involved in cell adhesion and motility. Positively regulates integrin-mediated adhesion of macrophages, particularly relevant for the inflammatory response in the lung.\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\u003eUse of recombinant standards to improve assay calibration and cross-study comparability.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eStructural component of specialized membrane microdomains known as tetraspanin-enriched microdomains, which act as platforms for receptor clustering and signaling. Essential for trafficking and compartmentalization of CD19 receptor on the surface of activated B cells. Upon initial encounter with microbial pathogens, enables the assembly of CD19-CR2\/CD21 and B cell receptor (BCR) complexes at signaling TERMs, lowering the threshold dose of antigen required to trigger B cell clonal expansion and antibody production. In T cells, facilitates the localization of CD247\/CD3 zeta at antigen-induced synapses with B cells, providing for costimulation and polarization toward T helper type 2 phenotype. Present in MHC class II compartments, may also play a role in antigen presentation. Can act both as positive and negative regulator of homotypic or heterotypic cell-cell fusion processes. Positively regulates sperm-egg fusion and may be involved in acrosome reaction. In myoblasts, associates with CD9 and PTGFRN and inhibits myotube fusion during muscle regeneration. In macrophages, associates with CD9 and beta-1 and beta-2 integrins, and prevents macrophage fusion into multinucleated giant cells specialized in ingesting complement-opsonized large particles. Also prevents the fusion of mononuclear cell progenitors into osteoclasts in charge of bone resorption. May regulate the compartmentalization of enzymatic activities. In T cells, defines the subcellular localization of dNTPase SAMHD1 and permits its degradation by the proteasome, thereby controlling intracellular dNTP levels. Also involved in cell adhesion and motility. Positively regulates integrin-mediated adhesion of macrophages, particularly relevant for the inflammatory response in the lung.\u003c\/p\u003e\u003ch2\u003eCommon research applications\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eStandard curve or spike-in reference for quantitative assays involving CD81\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 P60033 — UniProt — https:\/\/www.uniprot.org\/uniprotkb\/P60033 - NCBI Gene search: CD81 — NCBI — https:\/\/www.ncbi.nlm.nih.gov\/gene\/?term=CD81 - Ensembl search: CD81 — Ensembl — https:\/\/www.ensembl.org\/Multi\/Search\/Results?q=CD81 - 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":53053421781357,"sku":"CSB-MP004960HU-1MG","price":2212.0,"currency_code":"USD","in_stock":true},{"title":"100 ug","offer_id":53053563568493,"sku":"CSB-MP004960HU-100UG","price":342.0,"currency_code":"USD","in_stock":true},{"title":"20 ug","offer_id":53053563601261,"sku":"CSB-MP004960HU-20UG","price":136.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0949\/7424\/7277\/files\/CSB-MP004960HU-SDS.jpg?v=1772177702","url":"https:\/\/www.ebiohippo.com\/products\/recombinant-human-cd81-antigen-cd81-partial-bhp10507698","provider":"BioHippo","version":"1.0","type":"link"}