scholarly journals DIRECT EVIDENCE FOR HAGEMAN FACTOR (FACTOR XII) ACTIVATION BY BACTERIAL LIPOPOLYSACCHARIDES (ENDOTOXINS)

1974 ◽  
Vol 140 (3) ◽  
pp. 797-811 ◽  
Author(s):  
David C. Morrison ◽  
Charles G. Cochrane
Keyword(s):  
Escherichia Coli ◽  
Lipid A ◽  
Direct Evidence ◽  
Active Form ◽  
Fluid Phase ◽  
Factor Xii ◽  
Hageman Factor ◽  
High Concentrations ◽  
Bacterial Lipopolysaccharides ◽  
Factor Interaction

Purified precursor Hageman factor has been demonstrated to bind to soluble bacterial lipopolysaccharide (LPS, endotoxin) isolated from Escherichia coli 0111:B4, and this complex has been shown to have the capacity to convert prekallikrein to its active form. In addition, LPS-activated Hageman factor substantially reduces clotting times in XII-deficient plasma. The capacity to activate Hageman factor has been demonstrated to reside in the lipid A region of the LPS molecule. Activation of Hageman factor by LPS contrasts with fluid-phase activation (e.g., by kallikrein or trypsin) in that no cleavage to lower molecular weight fragments occurs. High concentrations of LPS inhibit the activity of Hageman factor, probably by a direct LPS-Hageman factor interaction.

scholarly journals The human complement system: assembly of the classical pathway C3 convertase

1980 ◽  
Vol 189 (1) ◽  
pp. 173-181 ◽  
Author(s):  
M A Kerr
Keyword(s):  
Direct Evidence ◽  
Gel Filtration ◽  
Fluid Phase ◽  
Classical Pathway ◽  
Human Complement ◽  
Stabilizing Effect ◽  
Excess Substrate ◽  
High Concentrations ◽  
Low Ionic Strength

The assembly of the classical pathway C3 convertase in the fluid phase has been studied. The enzyme is assembled from C2 and C4 on cleavage of these proteins by C1s. Once assembled, the enzyme activity decays rapidly. Kinetic evidence has been obtained that this decay is even more rapid than previously suggested (kdecay is 2.0 min-1 at 37 degrees C). As a result, optimal C3 convertase activity is only observed with high C1s levels, which result in rapid rates of cleavage of C2 and increased rates of formation of the C3 convertase. Using high concentrations of C1s at lower temperatures (22 degrees C) in the presence of excess substrate we have demonstrated kinetically that the enzyme comprises an equimolar complex of C4b and cleaved C2. We have obtained direct evidence from gel-filtration experiments for the role of C2a as the catalytic subunit of the enzyme. C2b appears to mediate the interaction between C4 (or C4b) and C2 at pH 8.5 and at low ionic strength where the interactions can easily be detected. It may therefore be important in the assembly of the enzyme, though it is not involved in the catalytic activity. The decay of the C3 convertase reflects the release of C2a from the C4b x (C2b) x C2a complex, and the stabilizing effect of iodine on the C3 convertase is therefore apparently one of stabilizing the C4b-C2z interaction, which is otherwise weak. C1s is not a part of the C3 convertase enzyme.

scholarly journals Studies on the inhibition of ellagic acid-activated Hageman factor (factor XII) and Hageman factor fragments

Blood ◽  
1981 ◽  
Vol 57 (1) ◽  
pp. 55-58
Author(s):  
OD Ratnoff
Keyword(s):  
Ellagic Acid ◽  
Lima Bean ◽  
Protamine Sulfate ◽  
Factor Xii ◽  
Single Chain ◽  
Hageman Factor ◽  
Hexadimethrine Bromide ◽  
Bean Trypsin Inhibitor ◽  
High Concentrations ◽  
Carboxy Terminal

Hageman factor (HF, factor XII) that has been exposed to Sephadex- ellagic acid gels is a single-chain species (HFea) with amidolytic properties for the synthetic substrate H-D-phenylalanyl-L-pipecolyl-L- arginine p-nitroanilide. Earlier we reported that amidolysis was suppressed by incubation of HFea with specific antiserum. The present study provides additional evidence that the amidolytic properties of preparations of HFea are ascribable to this substance through an examination of a number of protease inhibitors. HFea's amidolytic properties were inhibited by alpha 2-plasmin inhibitor, antithrombin III in the presence of heparin, and Cl esterase inhibitor (Cl-INH). Additionally, it was inhibited by popcorn inhibitor, leupeptin, hexadimethrine bromide, protamine sulfate, dansyl-arginine N-(3-ethyl- 1,5-pentanediyl) amide (DAPA), diisopropylphosphofluoridate (DFP), aprotinin, and at excessively high concentrations, soybean and lima bean trypsin inhibitors. The spectrum of action of agents that did or did not inhibit HFea supports the view that amidolysis by preparations of HFea is attributable to this enzyme. In general, the enzymatically active carboxy-terminal fragment of HF (HFf) was inhibited by the same agents that inhibited HFea, but aprotinin, protamine sulfate and hexadimethrine bromide were more effective against HFf than HFea, while the reverse was true of lima bean trypsin inhibitor.

scholarly journals Studies on the inhibition of ellagic acid-activated Hageman factor (factor XII) and Hageman factor fragments

Blood ◽  
1981 ◽  
Vol 57 (1) ◽  
pp. 55-58 ◽  
Author(s):  
OD Ratnoff
Keyword(s):  
Ellagic Acid ◽  
Lima Bean ◽  
Protamine Sulfate ◽  
Factor Xii ◽  
Single Chain ◽  
Hageman Factor ◽  
Hexadimethrine Bromide ◽  
Bean Trypsin Inhibitor ◽  
High Concentrations ◽  
Carboxy Terminal

Abstract Hageman factor (HF, factor XII) that has been exposed to Sephadex- ellagic acid gels is a single-chain species (HFea) with amidolytic properties for the synthetic substrate H-D-phenylalanyl-L-pipecolyl-L- arginine p-nitroanilide. Earlier we reported that amidolysis was suppressed by incubation of HFea with specific antiserum. The present study provides additional evidence that the amidolytic properties of preparations of HFea are ascribable to this substance through an examination of a number of protease inhibitors. HFea's amidolytic properties were inhibited by alpha 2-plasmin inhibitor, antithrombin III in the presence of heparin, and Cl esterase inhibitor (Cl-INH). Additionally, it was inhibited by popcorn inhibitor, leupeptin, hexadimethrine bromide, protamine sulfate, dansyl-arginine N-(3-ethyl- 1,5-pentanediyl) amide (DAPA), diisopropylphosphofluoridate (DFP), aprotinin, and at excessively high concentrations, soybean and lima bean trypsin inhibitors. The spectrum of action of agents that did or did not inhibit HFea supports the view that amidolysis by preparations of HFea is attributable to this enzyme. In general, the enzymatically active carboxy-terminal fragment of HF (HFf) was inhibited by the same agents that inhibited HFea, but aprotinin, protamine sulfate and hexadimethrine bromide were more effective against HFf than HFea, while the reverse was true of lima bean trypsin inhibitor.

scholarly journals Expression of wild-type and mutated rabbit osteopontin in Escherichia coli, and their effects on adhesion and migration of P388D1 cells

1995 ◽  
Vol 307 (1) ◽  
pp. 257-265 ◽  
Author(s):  
K Nasu ◽  
T Ishida ◽  
M Setoguchi ◽  
Y Higuchi ◽  
S Akizuki ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fluid Phase ◽  
Intradermal Injection ◽  
Polymorphonuclear Leucocyte ◽  
Alpha Subunit ◽  
Wild Type ◽  
Alpha Subunits ◽  
Leucocyte Migration ◽  
And Migration ◽  
Chemotactic Effect

Recombinant wild-type rabbit osteopontin (rOP) and the protein with an aspartate-to-glutamate transposition induced by a point mutation in the rabbit OP cDNA within the Gly-Arg-Gly-Asp-Ser (GRGDS) sequence were expressed in Escherichia coli and purified to homogeneity. P388D1 cells bound rOP in a saturable manner. rOP induced adhesion and haptotaxis of P388D1 cells, whereas mutated rabbit OP (rOPmut) did not. Anti-rOP IgG F(ab′)2 and synthetic GRGDS peptide inhibited rOP-mediated adhesion and haptotaxis of P388D1 cells. Fibronectin (FN)-mediated adhesion of P388D1 cells was markedly inhibited in the presence of fluid-phase rOP. Adhesion of P388D1 cells to rOP was significantly inhibited by anti-[alpha-subunits of VLA4 (alpha 4) and VLA5 (alpha 5)] monoclonal antibodies (mAbs), but not by anti-[alpha-subunit of vitronectin (VN) receptor (alpha V) or Mac-1 (alpha M)] mAb. Adhesion of P388D1 cells to FN and VN was significantly inhibited by anti-alpha V mAb but not anti-alpha 4, -alpha 5 or -alpha M mAb. Haptotaxis of P388D1 cells to rOP was significantly inhibited by anti-alpha V mAb, but not by anti-alpha 4, -alpha 5 and alpha M mAbs, whereas that to FN showed no inhibition with all three mAbs. Haptotaxis of P388D1 cells to VN was significantly inhibited by anti-alpha 5 and -alpha V mAbs but not by anti-alpha 4 and -alpha M mAbs. Similar features of inhibition of adhesion and haptotaxis of P388D1 cells to human OP were observed by mAbs. rOP had no chemotactic effect on P388D1 cells. Significant polymorphonuclear leucocyte migration was observed 3-12 h after intradermal injection of rOP into rabbits.

scholarly journals The Activity of Lipid A and Core Components of Bacterial Lipopolysaccharides in the Prevention of the Hypersensitive Response in Pepper

1997 ◽  
Vol 10 (7) ◽  
pp. 926-928 ◽  
Author(s):  
Mari-Anne Newman ◽  
Michael J. Daniels ◽  
J. Maxwell Dow
Keyword(s):  
Hypersensitive Response ◽  
Xanthomonas Campestris ◽  
Lipid A ◽  
Enteric Bacteria ◽  
Core Oligosaccharide ◽  
The Core ◽  
Minimal Structure ◽  
Core Components ◽  
Pre Treatment ◽  
Bacterial Lipopolysaccharides

Pre-treatment of leaves of pepper (Capsicum annuum) with lipopolysaccharide (LPS) preparations from enteric bacteria and Xanthomonas campestris could prevent the hypersensitive response caused by an avirulent X. campestris strain. By use of a range of deep-rough mutants, the minimal structure in Salmonella LPS responsible for the elicitation of this effect was determined to be lipid A attached to a disaccharide of 2-keto-3-deoxyoctulosonate; lipid A alone and the free core oligosaccharide from a Salmonella Ra mutant were not effective. For Xanthomonas, the core oligosaccharide alone had activity although lipid A was not effective. The results suggest that pepper cells can recognize different structures within bacterial LPS to trigger alterations in plant response to avirulent pathogens.

scholarly journals Macrophage activation by monosaccharide precursors of Escherichia coli lipid A.

1985 ◽  
Vol 82 (2) ◽  
pp. 282-286 ◽  
Author(s):  
M. Nishijima ◽  
F. Amano ◽  
Y. Akamatsu ◽  
K. Akagawa ◽  
T. Tokunaga ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Macrophage Activation ◽  
Lipid A
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