We studied binding and degradation of labeled platelet thrombospondin (TSP) by normal and variant bovine aorta endothelial (BAE) cells. [125I]-labeled TSP bound to cells at 37 degrees C in a specific, saturable, and time-dependent fashion. Incubation of cell monolayers with fluoresceinated TSP resulted in punctate cellular staining, but no staining of the extracellular matrix. Heparin, fucoidan...

OBJECTIVES Antithrombin is a progressive inhibitor of active factor X (FXa) and thrombin (FIIa). Its effect is 500- to 1,000-fold accelerated by heparin or heparan sulfate. Heterozygous type I (quantitative) and most type II (qualitative) antithrombin deficiencies highly increase the risk of venous thromboembolism (VTE), while homozygous mutations are lethal. The functional defect affecting the...

BACKGROUND There is a large increase in mast cell numbers in fibrotic lung tissue, suggesting that mast cells may play a part in the pathogenesis of pulmonary fibrosis. Glycosaminoglycans, such as heparan sulphate, that are structurally related to heparin (a mast cell product) are part of the extracellular matrix and known to regulate cell growth. Basic fibroblast growth factor is a heparin bin...

We show here that cell surface glycosaminoglycans (GAGs) are involved in the binding of stromal cell-derived factor (SDF)-1alpha to CD4(+)lymphoid CEM or monocytic U937 cells, inasmuch as pretreating the cells with heparitinase or chondroitinase inhibits SDF-1alpha binding by 40-41% and 31-35%, respectively. Soluble heparin or chondroitin sulfate partially but significantly inhibits SDF-1alpha ...

Heparan sulfate proteoglycans (HSPG) are obligatory for receptor binding and mitogenic activity of basic fibroblast growth factor (bFGF). The capacity of various species of heparin and heparan sulfate (HS) to promote bFGF receptor binding was investigated using both Chinese hamster ovary mutant cells deficient in cell surface HSPG and a soluble bFGF receptor-alkaline phosphatase fusion protein....

Factor IXa (FIXa) is known to have a binding site for heparin that has not been mapped by a mutagenesis study. By homology modeling based on structural data, we identified eight basic residues in the catalytic domain of FIXa that can potentially bind to heparin. These residues, Lys(98), Lys(126), Arg(165), Arg(170), Lys(173), Lys(230), Arg(233), and Lys(239) (chymotrypsin numbering) were substi...