Recombinant Human Neuropilin-1 Fc Chimera Protein, CF

Recombinant Human Neuropilin-1 Fc Chimera Protein, CF Summary

Product Specifications

Product Datasheets

Carrier Free

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Background: Neuropilin-1

Neuropilin-1 (Npn-1, also known as neuropilin and CD304) is a 130-140 kDa type I transmembrane (TM) glycoprotein that regulates axon guidance and angiogenesis (1-4). The full-length 923 amino acid (aa) human Npn-1 isoform 1 contains an 835 aa extracellular domain (ECD) that shows 92-95% aa identity with mouse, rat, bovine and canine Npn-1 (3, 4). The ECD contains two N-terminal CUB domains (termed a1a2), two domains with homology to coagulation factors V and VIII (b1b2) and a MAM (meprin) domain (c). C-terminally divergent splice variants with 704, 644, 609, and 551 aa lack the MAM and TM domains and are demonstrated or presumed to be soluble antagonists (1, 5-7). A 906 aa form lacks a TM segment, but secretion has not been found (8). The sema domains of Class III secreted semaphorins such as Sema3A bind Npn-1 a1a2 (9). Heparin, the heparin-binding forms of VEGF (VEGF 165, VEGF-B and VEGF-E), PlGF (PlGF2), and the C-terminus of Sema3 bind the b1b2 region (9, 10). Npn-1 and Npn-2 share 48% aa identity within the ECD and can form homo- and hetero-oligomers via interaction of their MAM domains (1). Neuropilins show partially overlapping expression in neuronal and endothelial cells during development (1, 2). Both neuropilins act as co-receptors with plexins, mainly plexin A3 and A4, to bind class III semaphorins that mediate axon repulsion (11). However, only Npn-1 binds Sema3A, and only Npn-2 binds Sema3F (1). Both are co-receptors with VEGF R2 (also called KDR or Flk-1) for VEGF 165 binding (1). Sema3A signaling can be blocked by VEGF 165, which has higher affinity for Npn-1 (12). Npn-1 is preferentially expressed in arteries during development or those undergoing remodeling (1, 2). Npn-1 is also expressed on dendritic cells and mediates DC-induced T cell proliferation (13). Npn-1 is a marker of CD4+ Treg cells and a population of CD8+ T-cells infiltrating solid tumors. Immunotherapies that block Npn-1 synergizes with anti-PD-1 to enhance CD8+ proliferation and response (14). There is evidence that Npn-1 with VEGF-A plays a role in stemness of breast cancer cell by activating Wnt/b-catenin pathway (15).

Related Research Areas

• Cytokine and Growth Factor Receptors on VSMC
• Neuronal Markers
• Plasmacytoid Dendritic Cells
• Regulatory T Cells (Tregs)
• Semaphorins, Plexin Receptors, and Related Molecules
• VEGF Family
• VEGF Receptors and Regulators on Endothelial Cells