Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02749 (beta2-glycoprotein I)
 836 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Anions with strong electro-negative charges, like sulphuric esters of polysaccharides (heparin, dextran sulphate M.W. 15 00), the sodium salt of polyanethol sulfonic acid (liquoid, Roche), anionic detergents (sodium dodecylsulphate, sodium oleate, sodium deoxycholate), and the sodium salt of phosphotungstic acid were added to human serum or citrated plasma. For each compound several final concentrations were adopted, the highest being 4%. By using microimmunoelectrophoresis and numerous specific antisera against human plasma proteins, it was demonstrated that at pH 8.60 anions increase electrophoretic mobility of the following antigens: lipoproteins alpha and beta; fibrinogen; beta 2-glycoprotein I; beta 2-glycoprotein II ; antithrombin III. All reagents utilized do not react with all these proteins; for instance, only detergents accelerate the migration rate of a lipoproteins. Besides, depending on the protein, this or that reagent may be the most active. Thus, in the polysulphate group, heparin has the highest affinity for antithrombin III, liquoid for fibrinogen and dextran sulphate for beta 2-glycoprotein I.
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PMID:[Polysulfates, anionic detergents, sodium phosphotungstate and electrophoretic mobility of plasmatic proteins]. 67 30

DNA-binding proteins were isolated from Yoshida ascites tumor fluid by chromatography on DNA-cellulose. This fraction represents 1-2% of the total ascites protein. Most of the DNA-binding proteins will bind to phosphocellulose as well. The proteins migrate by agarose gel electrophoresis at pH 8.6 as alpha and beta globulins. Quantitative immunoelectrophoresis revealed the presence of 12-18 proteins. SDS-polyacrylamide electrophoresis indicated molecular weights ranging from 3-10(4) to 10(6). Seven of the proteins were identified by specific immunoprecipitation as beta1-Eglobulin, beta2-glycoprotein I, fibrinogen split product E (fibrinogen E), coagulation factor XIII (factor XIII), alpha2-macroglobulin, IgG and IgM. Alpha1-antichymotrypsin might also be represented. In nuclear extracts of the tumor cells only factor XIII was present. With the exception of fibrinogen E and P5 all recognized DNA-binding proteins are present in normal rat plasma. With increasing tumor age the concentration of fibrinogen E, factor XIII, P5 and IgM increased both in ascites fluid and in plasma, while the concentration of other DNA-binding-proteins decreased or remained constant. Evidence is presented that the DNA- and phosphocellulose binding ascites protein fraction inhibit tumor cell growth. No inhibition was induced by corresponding protein fractions isolated from normal rat plasma.
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PMID:DNA-binding proteins in Yoshida ascites tumor fluid. 95 99

C-reactive protein (CRP) is thought to play an important role in immunomodulation. The exact biologic function of this pentraxin protein is, however, still unclear. Here we report experiments designed to further characterize the binding properties of CRP. Using purified human CRP it could be shown that CRP immobilized onto polystyrene surfaces or onto latex beads binds distinct plasma glycoproteins including IgG, asialofetuin, asialo-beta 2-glycoprotein I and, likewise, synthetic glycoproteins as a lectin, exhibiting binding specificity for terminal galactosyl residues of the glycoprotein glycans. Binding of CRP to IgA, IgM, IgG, asialofetuin, asialo-beta 2-glycoprotein I and to synthetic glycoproteins requires immobilization onto surfaces of both CRP and the ligand. Fibronectin and fibrinogen are bound by surface-immobilized CRP also in soluble phase. Comparing various mono-, di-, and trisaccharides as competitive inhibitors of the lectin binding activity of CRP, only beta-D-Gal-(1-3)-D-GalNAc, beta-D-Gal-(1-4)-D-GalNAc, and beta-D-Gal-(1-4)-beta-D-Gal-(1-4)-D-GlcNAc had significant inhibitory power at a concentration of 8 mmol/liter. Binding activity of CRP was pH-dependent with an optimum at pH 5 to 6 and was reduced by 90% when pH was shifted from 6 to the physiologic pH value of 7.4. CRP exhibited lectin-like properties with binding specificity for galactosyl residues also when bound to K-562 erythroleukemia cells. It is therefore suggested that CRP immobilized onto surfaces exhibits lectin activity toward galactosyl groups preferentially in a mildly acidic environment as present at sites of inflammation.
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PMID:Lectin specificity and binding characteristics of human C-reactive protein. 162 92

Previously developed murine monoclonal antibodies (MAbs) to human beta 2-glycoprotein I (beta 2 GPI), a plasma protein required for the binding of anti-phospholipid antibodies, were studied for anti-platelet reactivity and influence on platelet function. The six MAbs (IgG1 isotype) tested interacted with both intact and fixed platelets in a beta 2 GPI-dependent manner. Carbamylated beta 2 GPI was still recognized by MAbs but was unable to mediate platelet-antibody binding. MAbs induced aggregation and secretion responses of platelets in platelet-rich plasma (PRP) and whole blood, provided subthreshold concentrations of weak agonists (i.e. ADP or adrenaline) were added. When aggregation in PRP was evaluated by a counting technique instead of turbidometrically, the sole addition of MAbs led to a rapid fall in single platelets. Triggering gel-filtered platelets with MAbs together with beta 2 GPI, but not its carbamylated form, led to platelet activation after a lag time, as monitored by aggregometry, measurements of ATP and beta-thromboglobulin secretion and calcium mobilization. F(ab')2 fragments of one of the MAbs failed to activate platelets but inhibited the responses to the whole antibody. This process thus depends on MAbs binding to platelets through both Fab and Fc domains, as confirmed by the suppression of platelet responses upon pretreatment with the anti-Fc gamma RII MAb IV.3. Aggregation and secretion induced by MAbs plus beta 2 GPI did not require exogenous fibrinogen and were variably inhibited in the presence of acetyl salicylic acid, apyrase or Ca2+, depending on the concentrations used for the two proteins.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Platelet activating properties of murine monoclonal antibodies to beta 2-glycoprotein I. 823 45

IgG antibodies to cardiolipin and beta 2-glycoprotein I were looked for using an enzyme-linked immunosorbent assay (ELISA) in 19 patients with giant cell arteritis (meeting 1990 American College of Rheumatology criteria), including 16 with concomitant polymyalgia rheumatica (meeting Bird's criteria) and in three patients with isolated polymyalgia rheumatica. IgG anti-cardiolipin antibodies were demonstrated in eight patients (36%) and IgG anti-beta 2-glycoprotein I antibodies in two patients (9%) including one without anti-cardiolipin antibodies. Titers of anti-cardiolipin antibodies ranged from 27 to 190 units of IgG antiphospholipid antibodies (UGPL) (mean 71 UGPL). Of the eight patients with anti-cardiolipin antibodies, two had giant cell arteritis without polymyalgia rheumatica and six had polymyalgia rheumatica with clinical (n = 2) or histologic (n = 4) evidence of giant cell arteritis. None of the three patients with polymyalgia rheumatica but no giant cell arteritis had anti-cardiolipin or anti-beta 2 glycoprotein I antibodies. The VDRL was negative in the 14 patients who had this test. Tests for lupus anticoagulant were performed routinely, always with negative results. Among giant cell arteritis patients, those who tested positive for anticardiolipin antibody had significantly higher values for the erythrocyte sedimentation rate (p < 0.006) and for serum C-reactive protein (p < 0.03) and fibrinogen values (p = 0.05), and a trend toward higher platelet counts, as compared to those who tested negative for anticardiolipin antibody. The mean daily prednisone dose at the time of sampling was significantly lower in giant cell arteritis patients with anti-cardiolipin antibodies (p < 0.05); this difference may account for the apparent correlation between anti-cardiolipin antibodies and laboratory markers for inflammation. These data, as well as findings from serial measurements, suggest that anti-cardiolipin antibodies are present early in the course of giant cell arteritis and disappear within a few weeks of initiation of corticosteroid therapy in a dose of more than 25 mg prednisone per day. In this study, only one patient without anticardiolipin antibodies developed a cerebrovascular accident. Positive tests for anti-cardiolipin antibody or anti-beta 2 glycoprotein I antibody in a patient with polymyalgia rheumatica suggest a diagnosis of concomitant giant cell arteritis, which is usually symptomatic.
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PMID:Antibodies to cardiolipin and beta 2 glycoprotein I in patients with polymyalgia rheumatica and giant cell arteritis. 873 42

Systemic lupus erythematosus is a complex immunological and rheumatological disease that has numerous complications. Central to the pathogenesis of systemic lupus erythematosus is immune complex formation and deposition in blood vessels and end organs. This is a case report of an autopsy of a patient with systemic lupus erythematosus, end stage renal disease, peripheral vascular occlusive disease, pancreatitis, and aortitis. The aortitis was found to be immune complex mediated with deposition of IgG, C3, as well as fibrinogen in the wall of the aorta as shown by immunofluorescence. The hypercoagulable state of the patient is discussed with particular emphasis on the role of anticardiolipin antibodies, antiphospholipid antibodies, and anti-beta-2-glycoprotein I in the pathogenesis. This case is unique in that the immune complex mediated aortitis has not been described in the literature over the past 25 years. We recommend that the diagnosis of immune complex mediated aortitis be considered in the differential diagnosis of aortitis, particularly in the background of a patient with systemic lupus erythematosus.
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PMID:Lupus aortitis: a case report and review of the literature. 874 62

We have investigated beta2-glycoprotein I (beta2GPI) binding to platelet-derived microparticles (PMP) and its effect on GPIIb/IIIa. PMP were isolated from washed human platelets after stimulation with A23187, and analyzed by surface plasmon resonance spectroscopy. Beta2GPI as well as activated protein C (APC) or annexin V bound to PMP-coated sensorchips, demonstrating exposure of anionic phospholipids on immobilized PMP. Beta2GPI binding was impaired by calcium and occurred in a concentration-dependent manner with apparent k(on) = 2.6 x 10(4) M(-1) s(-1) and k(off) = 4.4 x 10(-3) s(-1), corresponding to a KD value of 1.7 x 10(-7) M. When analyzed by flow cytometry, the binding of certain mAbs specific for GPIIb and/or GPIIIa was reduced in the presence of beta2GPI but not of APC or annexin V, whereas the binding of anti-GPIb or anti-P-selectin mAbs, or of soluble fibrinogen remained unchanged. These results suggest a broad but specific influence of beta2GPI on GPIIb/IIIa immunoreactivity, and indicate that beta2GPI may act as a modulator of GPIIb/IIIa-dependent functions of PMP.
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PMID:Beta2-glycoprotein I binding to platelet microparticle membrane specifically reduces immunoreactivity of glycoproteins IIb/IIIa. 1124 54

We identified several low-abundance proteins of bovine colostrum and mature milk using the immunoabsorption technique and two-dimensional electrophoresis (2-DE) followed by microsequencing and mass spectrometry. Two major milk proteins, beta-casein and immunoglobulin G (IgG), were effectively removed from the milk using immunoabsorbents. Milk samples before and after immunoabsorption were separated by 2-DE. Protein identification of the spots on 2-DE was performed by either gel comparison, microsequencing, matrix-assisted laser desorption/ionization-time of flight mass-spectrometry (MALDI-TOF-MS), peptide mass fingerprinting or peptide sequencing using tandem MS by hybrid quadrupole/orthogonal acceleration time of flight-MS (Q-TOF). Significant differences in protein patterns were observed between the low-abundance proteins of colostrum and mature milk. In addition, several low-abundance proteins including fibrinogen beta-chain, chitinase 3-like 1, alpha-antitrypsin, complement C3 alpha-chain, gelsolin and apolipoprotein H were observed only in colostrum. However, the level of beta-casein fragments increased significantly during this lactation period. alpha-Lactalbumin and beta-lactoglobulin as well as some low-abundance proteins including bovine serum albumin, serotransferrin and lactoferrin were identified in both colostral and mature milk. Low-abundance proteins in bovine colostrum may have special physiologic relevance to the health and development of calves early in lactation.
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PMID:Identification of low-abundance proteins of bovine colostral and mature milk using two-dimensional electrophoresis followed by microsequencing and mass spectrometry. 1198 65

A phage display library made from Staphylococcus aureus DNA was sorted against a central venous catheter (CVC) that had been removed from a patient 2 days after insertion. After the first panning, approximately 50% of the clones encoded proteins known to interact with mammalian proteins. After the second and third pannings, fibrinogen-binding and beta2-glycoprotein I (beta2-GPI)-binding phage particles were clearly dominating. Proteins adsorbed to different CVCs were investigated using specific antibodies. Among the proteins probed for, fibrinogen was most abundant, but, interestingly, beta2-GPI was also detected on all tested CVCs.
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PMID:Sorting a Staphylococcus aureus phage display library against ex vivo biomaterial. 1535 15

We monitored the number of intravascular platelet-leukocyte aggregates (PLAs) and thrombotic occlusions (TOs) by intravascular microscopy in the mesentery of rats receiving antiphospholipid (aPL) immunoglobulin G (IgG) purified from the sera of patients with antiphospholipid syndrome. aPL IgG had no procoagulant effect, but it caused rapid endothelial deposition of fibrinogen, followed by PLA and TO in rats receiving an intraperitoneal injection of bacterial lipopolysaccharide 3 hours before IgG infusion. Anti-beta2-glycoprotein I-depleted aPL IgG failed to induce PLAs and TOs. C3 and C9 colocalized with aPL IgG on the mesenteric vessels. The number of PLAs and TOs was markedly reduced in C6-deficient rats and in animals treated with anti-C5 miniantibody, suggesting the contribution of the terminal complement (C) complex to the aPL antibody-mediated intravascular thrombosis. In conclusion, our data indicate that antibodies to beta2-glycoprotein I trigger coagulation subsequent to a priming proinflammatory factor and that the terminal C complex is the main mediator of the coagulation process.
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PMID:Thrombus formation induced by antibodies to beta2-glycoprotein I is complement dependent and requires a priming factor. 1595 88


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