{"product_id":"recombinant-human-complement-factor-i-cfi-partial-bhp10509633","title":"Recombinant Human Complement factor I (CFI), partial","description":"\u003ch2\u003eOverview\u003c\/h2\u003e \u003cp\u003eRecombinant Human Complement factor I (CFI), partial is a recombinant protein reagent derived from Homo sapiens (Human) and produced in E.coli. It is commonly used to support Immunology research by enabling binding assays, assay development and protein–protein interaction studies in controlled in vitro settings.\u003c\/p\u003e \u003ch2\u003eKey elements and design rationale\u003c\/h2\u003e\u003cul\u003e \u003cli\u003e\n\u003cstrong\u003eExpressed region:\u003c\/strong\u003e 239-316aa. Region selection can focus on functional domains, improve solubility, or isolate interaction surfaces for targeted studies.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eExpression system:\u003c\/strong\u003e E.coli. Expression host can influence folding and the presence\/absence of post-translational modifications.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eTag \/ fusion:\u003c\/strong\u003e N-terminal 10xHis-GST-tagged and C-terminal Myc-tagged. Tags can support purification and detection; evaluate potential tag effects when studying sensitive interactions.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eMolecular weight (reported):\u003c\/strong\u003e 43.4 kDa. Apparent size may vary with tags, processing, and gel conditions.\u003c\/li\u003e \u003c\/ul\u003e \u003cp\u003eWhen comparing results across batches or platforms, interpret signals in the context of construct design (region, tags) and expression host, especially for modification-dependent interactions.\u003c\/p\u003e \u003ch2\u003eBiological background\u003c\/h2\u003e \u003cp\u003eThe gene commonly associated with this target is \u003cstrong\u003eCFI\u003c\/strong\u003e. CFI refers to a protein target that is studied across multiple biological contexts; annotations and nomenclature can vary by species and isoform. This product corresponds to the Homo sapiens (Human) sequence context, which can be important when comparing homologs or orthologs across model systems. For curated functional annotations, domains, and sequence features, consult primary databases (e.g., UniProt\/NCBI) and the recent literature for the specific organism and isoform.\u003c\/p\u003e \u003ch2\u003eResearch relevance and current trends\u003c\/h2\u003e\u003cul\u003e \u003cli\u003eProfiling immune signaling nodes and cytokine pathways across cell types and activation states.\u003c\/li\u003e \u003cli\u003eStudying ligand–receptor interactions that shape immune cell communication and effector function.\u003c\/li\u003e \u003cli\u003eBuilding quantitative assays to compare pathway modulation by genetic or pharmacologic perturbations.\u003c\/li\u003e \u003c\/ul\u003e \u003cp\u003e\u003cstrong\u003eRelevance:\u003c\/strong\u003e Trypsin-like serine protease that plays an essential role in regulating the immune response by controlling all complement pathways. Inhibits these pathways by cleaving three peptide bonds in the alpha-chain of C3b and two bonds in the alpha-chain of C4b thereby inactivating these proteins . Essential cofactors for these reactions include factor H and C4BP in the fluid phase and membrane cofactor protein\/CD46 and CR1 on cell surfaces . The presence of these cofactors on healthy cells allows degradation of deposited C3b by CFI in order to prevent undesired complement activation, while in apoptotic cells or microbes, the absence of such cofactors leads to C3b-mediated complement activation and subsequent opsonization .\u003c\/p\u003e \u003ch2\u003eCommon research applications\u003c\/h2\u003e\u003cul\u003e \u003cli\u003eAssay and standard development for immunoassays or binding-based detection methods.\u003c\/li\u003e \u003cli\u003eProtein–protein interaction studies (e.g., receptor–ligand or complex assembly) using purified components.\u003c\/li\u003e \u003cli\u003eStructure–function analysis, including domain mapping or evaluation of sequence variants.\u003c\/li\u003e \u003c\/ul\u003e \u003cp\u003eIn quantitative assay development, changes in binding or activity readouts are typically interpreted relative to appropriate negative\/positive controls and, where possible, orthogonal assay formats that support the same conclusion.\u003c\/p\u003e \u003ch2\u003eNotes for experimental interpretation\u003c\/h2\u003e\u003cul\u003e \u003cli\u003eRecombinant constructs may represent a defined region (domain) rather than the full-length protein; interpret results in the context of the expressed region.\u003c\/li\u003e \u003cli\u003eTag or fusion elements can aid purification and detection but may influence binding surfaces or oligomerization; consider tag controls when relevant.\u003c\/li\u003e \u003cli\u003eSpecies and isoform differences can affect interaction partners and post-translational modifications; align experimental controls to the intended biological context.\u003c\/li\u003e \u003cli\u003eE. coli expression can limit eukaryotic post-translational modifications; for modification-dependent biology, interpret results accordingly.\u003c\/li\u003e \u003c\/ul\u003e \u003c!-- Sources (internal): - UniProtKB entry for P05156 — UniProt — https:\/\/www.uniprot.org\/uniprotkb\/P05156\/entry - NCBI Gene search (CFI) — NCBI — https:\/\/www.ncbi.nlm.nih.gov\/gene\/?term=CFI - PubMed search (CFI) — NCBI — https:\/\/pubmed.ncbi.nlm.nih.gov\/?term=CFI - RCSB PDB search (CFI) — RCSB PDB — https:\/\/www.rcsb.org\/search?query=CFI - Reactome Pathway Browser — Reactome — https:\/\/reactome.org\/ --\u003e","brand":"CUSABIO TECHNOLOGY LLC","offers":[{"title":"1 mg","offer_id":53065294446957,"sku":"CSB-EP005279HU1-1MG","price":2062.0,"currency_code":"USD","in_stock":true},{"title":"100 ug","offer_id":53065441018221,"sku":"CSB-EP005279HU1-100UG","price":480.0,"currency_code":"USD","in_stock":true},{"title":"20 ug","offer_id":53065441050989,"sku":"CSB-EP005279HU1-20UG","price":256.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0949\/7424\/7277\/files\/CSB-EP005279HU1-SDS.jpg?v=1772476544","url":"https:\/\/www.ebiohippo.com\/products\/recombinant-human-complement-factor-i-cfi-partial-bhp10509633","provider":"BioHippo","version":"1.0","type":"link"}