Plasminogen Interactions with Immobilized Fibrinogen

1989 ◽  
Vol 62 (04) ◽  
pp. 1078-1082 ◽  
Author(s):  
Burt Adelman ◽  
Patricia Ouynn
Keyword(s):  
Immunosorbent Assay ◽  
Aminocaproic Acid ◽  
Enzyme Linked Immunosorbent Assay ◽  
Binding Regions ◽  
Dose Dependent Fashion ◽  
Epsilon Aminocaproic Acid ◽  
Dose Dependent

SummaryThis report describes the binding of plasminogen to fibrinogen adsorbed onto polystyrene wells. Binding was determined by enzyme linked immunosorbent assay. Both glu- and lys-plasminogen bound to immobilized fibrinogen in a dose-dependent fashion. However, more lys- than glu-plasminogen bound when equal concentrations of either were added to immobilized fibrinogen. Plasminogen binding was inhibited by epsilon aminocaproic acid indicating that binding was mediated via lysine-binding regions of plasminogen. Soluble fibrinogen added in excess of immobilized fibrinogen did not compete for plasminogen binding but fibrinogen fragments produced by plasmin digestion of fibrinogen did. Treatment of immobilized fibrinogen with thrombin caused a small but significant (p <0.01) increase in plasminogen binding. These studies demonstrate that immobilized fibrinogen binds both glu- and lys-plasminogen and that binding is mediated via lysine-binding regions. These interactions may facilitate plasminogen binding to fibrinogen adsorbed on to surfaces and to cells such as platelets which bind fibrinogen.

scholarly journals Plasminogen binding to rat hepatocytes in primary culture and to thin slices of rat liver

Blood ◽  
1989 ◽  
Vol 74 (2) ◽  
pp. 729-736 ◽  
Author(s):  
SL Gonias ◽  
LL Braud ◽  
WA Geary ◽  
SR VandenBerg
Keyword(s):  
Primary Culture ◽  
Rat Liver ◽  
Anticoagulant Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Rat Hepatocytes ◽  
Aminocaproic Acid ◽  
Enzyme Linked Immunosorbent Assay ◽  
Thin Slices ◽  
The Media ◽  
Epsilon Aminocaproic Acid

Abstract Human 125I-plasminogen bound readily to rat hepatocytes in primary culture at 4 degrees C and at 37 degrees C. Binding was inhibited by lysine and reversed by lysine, epsilon-aminocaproic acid, or nonradiolabeled plasminogen. The Kd for binding of 125I-plasminogen to hepatocytes was 0.59 +/- 0.16 mumol/L, as determined from the saturation isotherm by nonlinear regression (r2 = 0.99) and the Scatchard transformation by linear regression (r2 = 0.93). The number of sites per cell was 14.1 +/- 1.1 x 10(6). Fibrinogen synthesis and secretion by hepatocytes was insufficient to account for the major fraction of plasminogen binding, as determined by enzyme-linked immunosorbent assay (ELISA). Polyacrylamide gel electrophoresis and trichloroacetic acid precipitation studies demonstrated that plasminogen is neither activated nor degraded when bound to hepatocytes at 37 degrees C. Thin slices of whole rat liver (500 microns), isolated and prepared totally at 4 degrees C, bound 125I-plasminogen. Binding was inhibited by lysine. 125I-albumin binding to liver slices was minimal and not inhibited by lysine. Activation of plasminogen by tissue plasminogen activator (t-PA) was enhanced by hepatocytes in primary culture. When lysine was included in the media, the enhanced rate of activation was no longer observed. After activation with t-PA, much of the plasmin remained associated with hepatocyte surfaces and was partially protected from inhibition by alpha 2-antiplasmin. These studies suggest that hepatocyte plasminogen binding sites may provide important surface anticoagulant activity.

scholarly journals Lactoferrin-Lipid A-Lipopolysaccharide Interaction: Inhibition by Anti-Human Lactoferrin Monoclonal Antibody AGM 10.14

1999 ◽  
Vol 67 (9) ◽  
pp. 4668-4672 ◽  
Author(s):  
Domenico Caccavo ◽  
Antonella Afeltra ◽  
Salvatore Pece ◽  
Giuseppe Giuliani ◽  
Marina Freudenberg ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Lipid A ◽  
Solid Phase ◽  
Bactericidal Effect ◽  
Enzyme Linked Immunosorbent Assay ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Dose Dependent Fashion ◽  
Bactericidal Activities ◽  
Dose Dependent

ABSTRACT Lactoferrin (LF) is a glycoprotein that exerts both bacteriostatic and bactericidal activities. The interaction of LF with lipopolysaccharide (LPS) of gram-negative bacteria seems to play a crucial role in the bactericidal effect. In this study, we evaluated, by means of an enzyme-linked immunosorbent assay, the binding of biotinylated LF to the S (smooth) and R (rough) (Ra, Rb, Rc, Rd1, Rd2, and Re) forms of LPS and different lipid A preparations. In addition, the effects of two monoclonal antibodies (AGM 10.14, an immunoglobulin G1 [IgG1] antibody, and AGM 2.29, an IgG2b antibody), directed against spatially distant epitopes of human LF, on the LF-lipid A or LF-LPS interaction were evaluated. The results showed that biotinylated LF specifically binds to solid-phase lipid A, as this interaction was prevented in a dose-dependent fashion by either soluble uncoupled LF or lipid A. The binding of LF to S-form LPS was markedly weaker than that to lipid A. Moreover, the rate of LF binding to R-form LPS was inversely related to core length. The results suggest that the polysaccharide O chain as well as oligosaccharide core structures may interfere with the LF-lipid A interaction. In addition, we found that soluble lipid A also inhibited LF binding to immobilized LPS, demonstrating that, in the whole LPS structure, the lipid A region contains the major determinant recognized by LF. AGM 10.14 inhibited LF binding to lipid A and LPS in a dose-dependent fashion, indicating that this monoclonal antibody recognizes an epitope involved in the binding of LF to lipid A or some epitope in its close vicinity. In contrast, AGM 2.29, even in a molar excess, did not prevent the binding of LF to lipid A or LPS. Therefore, AGM 10.14 may represent a useful tool for neutralizing selectively the binding of LF to lipid A. In addition, the use of such a monoclonal antibody could allow better elucidation of the consequences of the LF-lipid A interaction.

scholarly journals Assessment of Hageman factor activation in human plasma: quantification of activated Hageman factor-C1 inactivator complexes by an enzyme- linked differential antibody immunosorbent assay

Blood ◽  
1985 ◽  
Vol 66 (3) ◽  
pp. 636-641
Author(s):  
AP Kaplan ◽  
B Gruber ◽  
PC Harpel
Keyword(s):  
Complex Formation ◽  
Immunosorbent Assay ◽  
Time Dependent ◽  
Enzyme Linked Immunosorbent Assay ◽  
Contact Activation ◽  
Hageman Factor ◽  
Normal Plasma ◽  
Dose Dependent Increase ◽  
Dose Dependent

An enzyme-linked immunosorbent assay has been developed for the quantitation of activated Hageman factor-C1 inactivator (HF-C1 INH) complexes. Addition of increasing quantities of either of the major forms of activated Hageman factor (HFa or HFf) to normal plasma or to Hageman factor-deficient plasma leads to a dose-dependent increase in activated HF-C1 INH complexes. As little as 0.5 micrograms/mL of activated HF added to plasma can be detected, corresponding to activation of approximately 2% of plasma HF. The sensitivity of the assay is increased at least tenfold when complexes are formed in HF- deficient plasma, indicating competition between unactivated HF and activated HF-C1 INH complexes for binding to the antibody. Specificity is demonstrated in that addition of activated HF to hereditary angioedema plasma yields less than 1% of the activated HF-C1 INH complex formation obtained with normal plasma. Kaolin activation of HF- deficient plasma yields no detectable complex formation. Kaolin activation of prekallikrein-deficient plasma demonstrates a time- dependent increase in formation of activated HF-C1 INH complex consistent with the ability of HF in this plasma to autoactivate as the time of incubation with the surface is increased. Kaolin treatment of high-molecular weight (HMW) kininogen-deficient plasma yields an even more profound abnormality in the rate of formation of activated HF-C1 INH complexes reflecting the complex role of HMW kininogen in the initiation of contact activation. Although addition of corn inhibitor to plasma prevents activated HF-C1 INH complex formation, it does not inhibit activated HF sufficiently fast to prevent prekallikrein activation.

scholarly journals Assessment of Hageman factor activation in human plasma: quantification of activated Hageman factor-C1 inactivator complexes by an enzyme- linked differential antibody immunosorbent assay

Blood ◽  
1985 ◽  
Vol 66 (3) ◽  
pp. 636-641 ◽  
Author(s):  
AP Kaplan ◽  
B Gruber ◽  
PC Harpel
Keyword(s):  
Complex Formation ◽  
Immunosorbent Assay ◽  
Time Dependent ◽  
Enzyme Linked Immunosorbent Assay ◽  
Contact Activation ◽  
Hageman Factor ◽  
Normal Plasma ◽  
Dose Dependent Increase ◽  
Dose Dependent

Abstract An enzyme-linked immunosorbent assay has been developed for the quantitation of activated Hageman factor-C1 inactivator (HF-C1 INH) complexes. Addition of increasing quantities of either of the major forms of activated Hageman factor (HFa or HFf) to normal plasma or to Hageman factor-deficient plasma leads to a dose-dependent increase in activated HF-C1 INH complexes. As little as 0.5 micrograms/mL of activated HF added to plasma can be detected, corresponding to activation of approximately 2% of plasma HF. The sensitivity of the assay is increased at least tenfold when complexes are formed in HF- deficient plasma, indicating competition between unactivated HF and activated HF-C1 INH complexes for binding to the antibody. Specificity is demonstrated in that addition of activated HF to hereditary angioedema plasma yields less than 1% of the activated HF-C1 INH complex formation obtained with normal plasma. Kaolin activation of HF- deficient plasma yields no detectable complex formation. Kaolin activation of prekallikrein-deficient plasma demonstrates a time- dependent increase in formation of activated HF-C1 INH complex consistent with the ability of HF in this plasma to autoactivate as the time of incubation with the surface is increased. Kaolin treatment of high-molecular weight (HMW) kininogen-deficient plasma yields an even more profound abnormality in the rate of formation of activated HF-C1 INH complexes reflecting the complex role of HMW kininogen in the initiation of contact activation. Although addition of corn inhibitor to plasma prevents activated HF-C1 INH complex formation, it does not inhibit activated HF sufficiently fast to prevent prekallikrein activation.

scholarly journals The Surface Protein Srr-1 of Streptococcus agalactiae Binds Human Keratin 4 and Promotes Adherence to Epithelial HEp-2 Cells

2007 ◽  
Vol 75 (11) ◽  
pp. 5405-5414 ◽  
Author(s):  
Ulrike Samen ◽  
Bernhard J. Eikmanns ◽  
Dieter J. Reinscheid ◽  
Frédéric Borges
Keyword(s):  
Streptococcus Agalactiae ◽  
Surface Protein ◽  
Human Saliva ◽  
Binding Domain ◽  
Enzyme Linked Immunosorbent Assay ◽  
Host Proteins ◽  
Ionization Time ◽  
Bacterial Binding ◽  
Dose Dependent Fashion ◽  
Dose Dependent

ABSTRACT Streptococcus agalactiae is frequently the cause of bacterial sepsis and meningitis in neonates. In addition, it is a commensal bacterium that colonizes the mammalian gastrointestinal tract. During its commensal and pathogenic lifestyles, S. agalactiae colonizes and invades a number of host compartments, thereby interacting with different host proteins. In the present study, the serine-rich repeat protein Srr-1 from S. agalactiae was functionally investigated. Immunofluorescence microscopy showed that Srr-1 was localized on the surface of streptococcal cells. The Srr-1 protein was shown to interact with a 62-kDa protein in human saliva, which was identified by matrix-assisted laser desorption ionization-time-of-flight analysis as human keratin 4 (K4). Immunoblot and enzyme-linked immunosorbent assay experiments allowed us to narrow down the K4 binding domain in Srr-1 to a region of 157 amino acids (aa). Furthermore, the Srr-1 binding domain of K4 was identified in the C-terminal 255 aa of human K4. Deletion of the srr-1 gene in the genome of S. agalactiae revealed that this gene plays a role in bacterial binding to human K4 and that it is involved in adherence to epithelial HEp-2 cells. Binding to immobilized K4 and adherence to HEp-2 cells were restored by introducing the srr-1 gene on a shuttle plasmid into the srr-1 mutant. Furthermore, incubation of HEp-2 cells with the K4 binding domain of Srr-1 blocked S. agalactiae adherence to epithelial cells in a dose-dependent fashion. This is the first report describing the interaction of a bacterial protein with human K4.

scholarly journals Plasminogen binding to rat hepatocytes in primary culture and to thin slices of rat liver

Blood ◽  
1989 ◽  
Vol 74 (2) ◽  
pp. 729-736 ◽  
Author(s):  
SL Gonias ◽  
LL Braud ◽  
WA Geary ◽  
SR VandenBerg
Keyword(s):  
Primary Culture ◽  
Rat Liver ◽  
Anticoagulant Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Rat Hepatocytes ◽  
Aminocaproic Acid ◽  
Enzyme Linked Immunosorbent Assay ◽  
Thin Slices ◽  
The Media ◽  
Epsilon Aminocaproic Acid

Human 125I-plasminogen bound readily to rat hepatocytes in primary culture at 4 degrees C and at 37 degrees C. Binding was inhibited by lysine and reversed by lysine, epsilon-aminocaproic acid, or nonradiolabeled plasminogen. The Kd for binding of 125I-plasminogen to hepatocytes was 0.59 +/- 0.16 mumol/L, as determined from the saturation isotherm by nonlinear regression (r2 = 0.99) and the Scatchard transformation by linear regression (r2 = 0.93). The number of sites per cell was 14.1 +/- 1.1 x 10(6). Fibrinogen synthesis and secretion by hepatocytes was insufficient to account for the major fraction of plasminogen binding, as determined by enzyme-linked immunosorbent assay (ELISA). Polyacrylamide gel electrophoresis and trichloroacetic acid precipitation studies demonstrated that plasminogen is neither activated nor degraded when bound to hepatocytes at 37 degrees C. Thin slices of whole rat liver (500 microns), isolated and prepared totally at 4 degrees C, bound 125I-plasminogen. Binding was inhibited by lysine. 125I-albumin binding to liver slices was minimal and not inhibited by lysine. Activation of plasminogen by tissue plasminogen activator (t-PA) was enhanced by hepatocytes in primary culture. When lysine was included in the media, the enhanced rate of activation was no longer observed. After activation with t-PA, much of the plasmin remained associated with hepatocyte surfaces and was partially protected from inhibition by alpha 2-antiplasmin. These studies suggest that hepatocyte plasminogen binding sites may provide important surface anticoagulant activity.

Alterations in Vascular Endothelial Cell-related Plasma Proteins In Thalassaemic Patients and their Correlation with Clinical Symptoms

1995 ◽  
Vol 74 (04) ◽  
pp. 1045-1049 ◽  
Author(s):  
P Butthep ◽  
A Bunyaratvej ◽  
Y Funahara ◽  
H Kitaguchi ◽  
S Fucharoen ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Immunosorbent Assay ◽  
Plasma Proteins ◽  
Clinical Symptoms ◽  
Vascular Endothelial Cells ◽  
Vascular Endothelial Cell ◽  
Enzyme Linked Immunosorbent Assay ◽  
Vascular Endothelial ◽  
Leg Ulcers

SummaryAn increased level of plasma thrombomodulin (TM) in α- and β- thalassaemia was demonstrated using an enzyme-linked immunosorbent assay (ELISA). Nonsplenectomized patients with β-thalassaemia/ haemoglobin E (BE) had higher levels of TM than splenectomized cases (BE-S). Patients with leg ulcers (BE-LU) were found to have the highest increase in TM level. Appearance of larger platelets in all types of thalassaemic blood was observed indicating an increase in the number of younger platelets. These data indicate that injury of vascular endothelial cells is present in thalassaemic patients.

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