The Sulfate Groups of Chondroitin Sulfate- and Heparan Sulfate-containing Proteoglycans in Neutrophil Plasma Membranes Are Novel Binding Sites for Human Leukocyte Elastase and Cathepsin G

摘要: Abstract Human leukocyte elastase (HLE) and cathepsin G (CG) are expressed at high levels on the surface of activated human neutrophils (PMN) in catalytically active but inhibitor-resistant forms having potential to contribute tissue injury. Herein we have investigated mechanisms by which HLE CG bind PMN plasma membranes. 125I-Labeled 0 °C a saturable reversible manner (KD = 5.38 4.36 × 10-7 m 11.5 8.1 106 binding sites/cell, respectively). Incubation with radiolabeled presence 200-fold molar excess unlabeled HLE, CG, myeloperoxidase, lactoferrin, proteinase 3, phenylmethylsulfonyl fluoride (PMSF)-inactivated or PMSF-inactivated inhibited ligands. This indicates that these granule proteins share sites functional not required for their PMN. The sulfate groups heparan sulfate- chondroitin sulfate-containing proteoglycans since was incubating 1) trypsin, chondroitinase ABC, heparitinases, other glycanases, 2) purified sulfates, sulfate, sulfated molecules, non-sulfated glycans. Thus, low affinity, volume well suited concentrations serine proteinases released from degranulating