Plasma glycoprotein that binds a number of ligands such as heme, heparin, heparan sulfate, thrombospondin, plasminogen, and divalent metal ions. Inhibits rosette formation. Acts as an adapter protein and implicated in regulating many processes such as immune complex and pathogen clearance, cell adhesion, angiogenesis, coagulation and fibrinolysis. Mediates clearance of necrotic cells through enhancing the phagocytosis of necrotic cells in an heparan sulfate-dependent pathway. This process can be regulated by the presence of certain HRG ligands such as heparin and zinc ions. Binds to IgG subclasses of immunoglobins containing kappa and lambda light chains with different affinities regulating their clearance and inhibiting the formation of insoluble immune complexes. Tethers plasminogen to the cell surface. Binds T-cells and alters the cell morphology. Modulates angiogenesis by blocking the CD6-mediated antiangiongenic effect of thrombospondins, THBS1 and THBS2.
Specificity
Natural and recombinant Human Histidine-rich glycoprotein
Interacts (via the HRR domain) with TPM1; the interaction appears to contribute to the antiangiogenic properties of the HRR domain. Interacts with THBS2; the interaction blocks the antiangiogenic effect of THBS2 with CD36 (By similarity). Interacts with THBS1 (via the TSP type I repeats); the interaction blocks the antiangiogenic effect of THBS1 with CD3. Interacts with PLG (via its Kringle domains); the interaction tethers PLG to the cell surface and enhances its activation. Interacts with HPSE; the interaction is enhanced at acidic pH, partially inhibits binding of HPSE to cell surface receptors and modulates its enzymatic activity. Interacts (via the HRR domain) with TMP1; the interaction partially mediates the antiangiogenic properties of HRG. Interacts with kappa and lambda light chains of IgG molecules. Interacts with ATP5A1; the interaction occurs on the surface of T-cells and alters their cell morphology in concert with CONA. Binds IgG molecules containing kappa and lambda light chains and inhibits the formation of insoluble immunoglobulin complexes. Interacts with F12; the interaction, which is enhanced in the presence of zinc ions and inhibited by heparin-binding to HRG, inhibits factor XII autoactivation and contact-initiated coagulation.