Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.6.4 (chondroitinase)
 2,039 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The media layer of the arterial cryo-cross sections, is defective for vWf-dependent platelet adhesion. Exposure of the same layer by stripping off the most inner portions of the vessel wall results in a highly thrombogenic surface. Stripping or balloon dilation was applied to porcine arteries prior to functional assays. Cryosections of treated or untreated arteries were perfused with porcine blood at 3,350 s(-1) and platelet deposition was detected by indirect immunofluorescence. Following balloon dilation, vWf-dependent platelet deposition increased; covering 9.08 +/- 1.36% of the total media surface area, this value for untreated vessels was 0.88 +/- 0.14%. A 10-fold increase was also found in the binding of vWf-coated fluorescent beads to the media. In addition to mechanical procedures, treatment by serine-proteases like trypsin, chymotrypsin and proteinase 3, or by chondroitinase ABC, but not by heparitinase also resulted in a 7-10-fold increase in platelet coverage over the media. Collagen in the media may be complexed with another vessel wall component shielding the vWf-binding sites. Mechanical or biochemical processes unmask these sites, and increase the thrombogenicity of the vessel wall.
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PMID:Physical and enzymatic perturbation of the architecture of the Tunica media destroys its inherent thromboresistance. 1242 2

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 the potential to contribute to tissue injury. Herein we have investigated the mechanisms by which HLE and CG bind to PMN plasma membranes. (125)I-Labeled HLE and CG bind to PMN at 0 degrees C in a saturable and reversible manner (K(D) = 5.38 and 4.36 x 10(-7) m and 11.5 and 8.1 x 10(6) binding sites/cell, respectively). Incubation of PMN with radiolabeled HLE and CG in the presence of a 200-fold molar excess of unlabeled HLE, CG, myeloperoxidase, lactoferrin, proteinase 3, phenylmethylsulfonyl fluoride (PMSF)-inactivated HLE, or PMSF-inactivated CG inhibited binding of radiolabeled ligands. This indicates that these PMN granule proteins share binding sites on PMN and that functional active sites of HLE and CG are not required for their binding to PMN. The sulfate groups of heparan sulfate- and chondroitin sulfate-containing proteoglycans are the PMN binding sites for HLE and CG since binding of HLE and CG to PMN was inhibited by incubating PMN with 1) trypsin, chondroitinase ABC, and heparitinases, but not other glycanases, and 2) purified chondroitin sulfates, heparan sulfate, and other sulfated molecules, but not with non-sulfated glycans. Thus, heparan sulfate- and chondroitin sulfate-containing proteoglycans are low affinity, high volume PMN surface binding sites for HLE and CG, which are well suited to bind high concentrations of active serine proteinases released from degranulating PMN.
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PMID: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. 1738 12