New Members of the Angiopoietin-like Family are Now Available!

Angiopoietin-like proteins (ANGPTL1-8) are secreted glycoproteins that are structurally related to Angiopoietins. They play roles in angiogenesis, lipid metabolism, hematopoietic stem cell expansion, inflammation, and cancer biology. ANGPTLs all contain an N-terminal coiled-coil domain which mediates oligomerization, and a C-terminal fibrinogen-like domain. ANGPTL8 is the only exception and doesn’t have the C-terminal domain. Unlike angiopoietins, which are known to signal through the tyrosine kinases Tie1 or Tie 2, Angiopoietin-like proteins have long been considered orphan ligands.

Recently, ANGPTL1, 2, 5, and 7 were shown to bind to human leukocyte immunoglobulin like receptor B2 (LILRB2), resulting in enhancement of human hematopoietic stem cell proliferation and expansion1. R&D Systems scientists have also shown that binding to LILR receptors is more widespread.

Human ANGPTL2 Binds the LILRB2 Receptor. An ELISA binding assay was used to show that Recombinant Human ANGPLT2 (Catalog # 9746-AN) binds to Recombinant Human LILRB2 (Catalog # 2078-T4). The ED₅0 for this interaction falls within 0.02-0.12 µg/mL.

Recombinant Human ANGPTL2 (Catalog # 9746-AN) Induces Proliferation in Primary Rat Liver Mononuclear Cells.  ANGPTL2 enhances proliferation of E16 rat liver mononuclear cells grown, in vitro, in the presence of Recombinant Mouse SCF/c-kit Ligand (Catalog # 455-MC), Recombinant Mouse Thrombopoietin/TPO (Catalog # 488-TO), and Recombinant Mouse Flt-3 Ligand (Catalog # 427-FL).

Human ANGPLT2 C-terminal Fragment Binds the LILRB2 Receptor. An ELISA binding assay was used to show that Recombinant Human ANGPLT2 C-terminal Fragment (Catalog # 9795-AN) binds to Recombinant Human LILRB2 (Catalog # 2078-T4). The ED₅₀ for this interaction falls within 4-24 ng/mL.

Mouse ANGPLT2 C-terminal Fragmment Binds the LILRB2 Receptor. An ELISA binding assay was used to show that Recombinant Mouse ANGPLT2 C-terminal Fragment (Catalog # 9796-AN) binds to Recombinant Human LILRB2 (Catalog # 2078-T4). The ED₅₀ for this interaction falls within 4-24 ng/mL.

Mouse ANGPLT4 C-terminal Fragmment Binds the LILRB2 Receptor. An ELISA binding assay was used to show that Recombinant Mouse ANGPLT4 C-terminal Fragment (Catalog # 9797-AN) binds to Recombinant Human LILRB2 (Catalog # 2078-T4). The ED₅₀ for this interaction falls within 0.09-0.54 µg/mL.

References

1. Zheng, J. et al. (2012) Inhibitory receptors bind ANGPTLs and support blood stem cells and leukaemia development. Nature 485:656.