Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.7 (plasmin)
 9,023 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The interactions between Helicobacter pylori spiral and coccoid forms, extracellular matrix (ECM) and plasma proteins were studied in an 125I-labelled protein assay. The range of binding of collagen V, plasminogen, human lactoferrin (HLf) and vitronectin to coccoid forms of H. pylori NCTC 11637 was 26-48%. In contrast, binding of radiolabelled fibronectin and collagen types I and III was low (3-8%). The coccoid forms of 14 strains of H. pylori showed significant HLf binding (median 26%). With plasminogen, no significant difference was found between binding to the coccoid (median = 13%) and spiral (median = 12%) forms, of 13 of the 14 strains of H. pylori tested; the exception was strain NCTC 11637. 125I-plasminogen showed a dose-dependent binding to both the coccoid and spiral forms. Plasminogen binding to both forms was specific; the binding was inhibited by non-labelled plasminogen, plasmin, lysine, EACA (epsilon-aminocaproic acid) but not by fetuin or various carbohydrates. Similarly, HLf binding was found to be specific and was inhibited by non-labelled HLf and BLf. The coccoid forms showed either similar or enhanced ECM binding capabilities compared with the spiral forms. As the binding of ECM proteins may be an important mechanism of tissue adhesion for various pathogenic bacteria, the coccoid differentiated form of H. pylori can be considered as an infective form in the pathogenesis of helicobacter infection and type B gastritis.
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PMID:Binding of human plasminogen and lactoferrin by Helicobacter pylori coccoid forms. 895 46

The binding of iodine-labelled plasminogen to Helicobacter pylori CCUG 17874 was characterized. Inhibition of the binding was observed after preincubation of H. pylori cells with nonradiolabelled plasminogen, lysine, or the lysine analogue epsilon-aminocaproic acid. Fragments of plasminogen, kringles 1 to 3, kringle 4, and mini-plasminogen, were also studied as potential inhibitors. Mini-plasminogen caused total inhibition of the plasminogen binding, while the other fragments caused only partial inhibition. These findings suggest that H. pylori binds specifically the fifth kringle structure of the plasminogen molecule. Plasminogen binding to H. pylori seems to be independent of culture media and independent of the presence of the cytotoxin-associated CagA antigen. Immunoblot analysis identified two plasminogen binding proteins of 57 and 42 kDa. Scatchard plot analysis revealed one binding mechanism with a Kd value of 7 x 10(-7) M. Conversion of H. pylori cell-bound plasminogen to plasmin in the presence of a tissue-type plasminogen activator was demonstrated by digestion of the chromogenic substrate S-2251. No activation was noted when plasminogen or tissue-type plasminogen activator was incubated with H. pylori cells alone. Formation of H. pylori cell surface-bound plasmin may be important to provide a powerful proteolytic mechanism for gastric tissue penetration in type B gastritis and peptic ulcer disease, since plasmin degrades not only fibrin but also extracellular matrix proteins such as various collagens and fibronectin.
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PMID:Plasminogen binding and activation at the surface of Helicobacter pylori CCUG 17874. 974 6

Helicobacter pylori is the causative agent of chronic gastritis, peptic ulcer, and gastric malignancies. A number of virulence factors have been described including several adhesins, a cytotoxin, neutrophil-activating protein, and expression of binding of extracellular matrix proteins, like collagen type IV, laminin, and vitronectin. H. pylori strains commonly express binding of soluble plasminogen. Coccoid forms also express binding. Plasminogen binding was optimal at pH 7.0. The binding is mediated by two cell surface proteins of 42 and 57 kDa. Scatchard plot analysis showed a straight line with a K(d) of 7 x 10(-7) M. Lysine and E-aminocaproic acid inhibited binding. The binding domain on the plasminogen molecule is the fifth kringle, miniplasminogen. Plasminogen is converted to plasmin by tissue plasminogen activator. During H. pylori infection the activity of tissue plasminogen activator is decreased and that of urokinase increased. This is reversed after eradication therapy. The plasminogen binding and conversion to plasmin is the only proteolytic activity of H. pylori, and may enhance tissue penetration and be involved in carcinogenesis.
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PMID:Helicobacter pylori interactions with plasminogen. 1081 76