Biosynthesis of functionally active heparin cofactor II by a human hepatoma-derived cell line.
Human plasma heparin cofactor II (HCII) inhibits thrombin by rapidly forming a stable, equimolar complex in the presence of heparin or dermatan sulfate. Cultured human hepatoma-derived cells (PLC/PRF-5) secreted (approximately equal to 200 ng/ml in 3 days) a protein of MW - 72 kD that was immunoisolated and immunoblotted with anti-HCII, co-migrated on SDS-PAGE with human plasma HCII, and formed covalent complexes with thrombin (MW - 101 kD) in the presence but not absence of heparin or dermatan sulfate; these complexes co-migrated with those obtained by incubating thrombin with human plasma under the same conditions. HCII was not detectable (less than 0.13 ng/ml) in post-culture medium from cultured human umbilical vein endothelial cells or human foreskin fibroblasts.
D000918:Antibody Specificity; D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D002460:Cell Line; D003871:Dermatan Sulfate / Q000378:metabolism; D006023:Glycoproteins / Q000096:biosynthesis* / Q000276:immunology; D006493:Heparin / Q000378:metabolism; D015844:Heparin Cofactor II; D006801:Humans; D007122:Immunoelectrophoresis; D008113:Liver Neoplasms / Q000378:metabolism*; D008715:Methionine / Q000378:metabolism; D008970:Molecular Weight; D013917:Thrombin / Q000378:metabolism
D006023:Glycoproteins; D003871:Dermatan Sulfate; D015844:Heparin Cofactor II; D006493:Heparin; D008715:Methionine; D013917:Thrombin