Siglec-1/CD169 Protein, Human (HEK293, His)

Siglec-1/CD169 is a macrophage-specific adhesion molecule that mediates sialic acid-dependent binding to immune cells, limiting bacterial dissemination and enhancing phagocytosis. In addition to bacterial interactions, it facilitates the uptake of enveloped viruses and promotes macrophage-to-T cell dissemination. Siglec-1/CD169 Protein, Human (HEK293, His) is the recombinant human-derived Siglec-1/CD169 protein, expressed by HEK293 , with C-His labeled tag.

Siglec-1/CD169 emerges as a macrophage-restricted adhesion molecule with a pivotal role in mediating sialic acid-dependent binding to various immune cells, including granulocytes, monocytes, natural killer cells, B-cells, and CD8 T-cells. Its significance lies in limiting bacterial dissemination by engaging sialylated bacteria, thereby promoting effective phagocytosis and antigen presentation crucial for the adaptive immune response. Beyond bacterial interactions, Siglec-1 is implicated in the uptake of enveloped viruses through sialic acid recognition, leading to the formation of intracellular compartments filled with virions (VCCs). This facilitates macrophage-to-T-cell transmission of viruses, including HIV-1 or SARS-CoV-2. Acting as an endocytic receptor, Siglec-1 employs clathrin-dependent endocytosis, exhibiting a preference for alpha-2,3-linked sialic acid. Notably, it binds to SPN/CD43 on T-cells and may play a role in hemopoiesis. Additionally, Siglec-1 contributes to the inhibition of antiviral innate immunity by promoting TBK1 degradation via TYROBP and TRIM27-mediated ubiquitination. In the context of microbial infection, it facilitates viral cytoplasmic entry into activated dendritic cells by recognizing sialylated gangliosides present on the viral membrane.

Measured by the ability of the immobilized protein to support the adhesion of THP-1.The ED₅₀ for this effect is 2.863 µg/mL, corresponding to a specific activity is 349.284 units/mg.

Human

HEK293

C-10*His

Q9BZZ2-1 (S20-Q1641)

6614  [NCBI]

Extracellular Domain

SWGVSSPQDVQGVKGSCLLIPCIFSFPADVEVPDGITAIWYYDYSGQRQVVSHSADPKLVEARFRGRTEFMGNPEHRVCNLLLKDLQPEDSGSYNFRFEISEVNRWSDVKGTLVTVTEEPRVPTIASPVELLEGTEVDFNCSTPYVCLQEQVRLQWQGQDPARSVTFNSQKFEPTGVGHLETLHMAMSWQDHGRILRCQLSVANHRAQSEIHLQVKYAPKGVKILLSPSGRNILPGELVTLTCQVNSSYPAVSSIKWLKDGVRLQTKTGVLHLPQAAWSDAGVYTCQAENGVGSLVSPPISLHIFMAEVQVSPAGPILENQTVTLVCNTPNEAPSDLRYSWYKNHVLLEDAHSHTLRLHLATRADTGFYFCEVQNVHGSERSGPVSVVVNHPPLTPVLTAFLETQAGLVGILHCSVVSEPLATLVLSHGGHILASTSGDSDHSPRFSGTSGPNSLRLEIRDLEETDSGEYKCSATNSLGNATSTLDFHANAARLLISPAAEVVEGQAVTLSCRSGLSPTPDARFSWYLNGALLHEGPGSSLLLPAASSTDAGSYHCRARDGHSASGPSSPAVLTVLYPPRQPTFTTRLDLDAAGAGAGRRGLLLCRVDSDPPARLQLLHKDRVVATSLPSGGGCSTCGGCSPRMKVTKAPNLLRVEIHNPLLEEEGLYLCEASNALGNASTSATFNGQATVLAIAPSHTLQEGTEANLTCNVSREAAGSPANFSWFRNGVLWAQGPLETVTLLPVARTDAALYACRILTEAGAQLSTPVLLSVLYPPDRPKLSALLDMGQGHMALFICTVDSRPLALLALFHGEHLLATSLGPQVPSHGRFQAKAEANSLKLEVRELGLGDSGSYRCEATNVLGSSNTSLFFQVRGAWVQVSPSPELQEGQAVVLSCQVHTGVPEGTSYRWYRDGQPLQESTSATLRFAAITLTQAGAYHCQAQAPGSATTSLAAPISLHVSYAPRHVTLTTLMDTGPGRLGLLLCRVDSDPPAQLRLLHGDRLVASTLQGVGGPEGSSPRLHVAVAPNTLRLEIHGAMLEDEGVYICEASNTLGQASASADFDAQAVNVQVWPGATVREGQLVNLTCLVWTTHPAQLTYTWYQDGQQRLDAHSIPLPNVTVRDATSYRCGVGPPGRAPRLSRPITLDVLYAPRNLRLTYLLESHGGQLALVLCTVDSRPPAQLALSHAGRLLASSTAASVPNTLRLELRGPQPRDEGFYSCSARSPLGQANTSLELRLEGVRVILAPEAAVPEGAPITVTCADPAAHAPTLYTWYHNGRWLQEGPAASLSFLVATRAHAGAYSCQAQDAQGTRSSRPAALQVLYAPQDAVLSSFRDSRARSMAVIQCTVDSEPPAELALSHDGKVLATSSGVHSLASGTGHVQVARNALRLQVQDVPAGDDTYVCTAQNLLGSISTIGRLQVEGARVVAEPGLDVPEGAALNLSCRLLGGPGPVGNSTFAWFWNDRRLHAEPVPTLAFTHVARAQAGMYHCLAELPTGAAASAPVMLRVLYPPKTPTMMVFVEPEGGLRGILDCRVDSEPLASLTLHLGSRLVASSQPQGAPAEPHIHVLASPNALRVDIEALRPSDQGEYICSASNVLGSASTSTYFGVRALHRLHQFQQ

Approximately 130-180 kDa, based on SDS-PAGE under reducing conditions, due to the glycosylation.

• 
  ≥ 95%, as determined by reducing SDS-PAGE.

Lyophilized powder

Lyophilized a 0.22 μm filtered solution of 20 mM MES,150 mM NaCl, pH 5.5, 10% trehalose.

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O.

Stored at -20°C for 2 years from date of receipt. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US; may vary elsewhere.