Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Antisera against tetrahydronaphthalenols, which are conformationally rigid derivatives of adrenergic catecholamine, were produced in rabbits immunized with trans-5-amino-6-hydroxy-2-isopropylamino-1,2,3,4-tetrahydronaphthalene-1 -ol (I) conjugated to succinylated bovine serum albumin at the C5 position on the tetralin ring. Antisera were screened by immunodiffusion and further characterized by passive hemagglutination assay using erythrocytes sensitized with trans-I-ovalbumin conjugate and by enzyme immunoassay using trans-I-beta-galactosidase conjugate. Cross-reactivity studies indicated that the antiserum was highly specific for the tetralin structure and for substitution at the C2 position. The antiserum also selectively discriminated the stereoisomers about the C1-C2 bond. The anti-trans-I serum was used to develop EIA for trans-5-hydroxymethyl-6-hydroxy-2-isopropylamino-1,2,3,4-tetrahydronapht halene- 1-ol (IIb), which exhibited strong beta-stimulating activity fairly selective to tracheal muscle, since it recognized trans-IIb to the same degree as trans-I. The assay could detect as little as 100 pg of this compound. The mean recovery of trans-IIb added to plasma was 105%, and values for plasma trans-IIb determined by this immunoassay correlated well with those determined by gas chromatography-mass spectrometry.
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PMID:Enzyme immunoassay of a beta-adrenergic agent using beta-galactosidase as label. 4 9

Homogeneous enzyme immunoassays have played a major role in the development of simple and easy to use diagnostic tests for clinical laboratory instrumentation. A novel homogeneous enzyme immunoassay system, CEDIA, has been developed using enzyme fragments prepared by recombinant DNA technology. Two separate genes are engineered to express two separate polypeptide fragments: enzyme-donor (ED) and enzyme-acceptor (EA). These fragments can spontaneously recombine to form active beta-galactosidase enzyme. Ligands can be attached to the ED peptide in such a way that the degree of recombination is controlled by the binding of anti-ligand antibodies to the enzyme donor-ligand conjugate. CEDIA methodology is based on the competition between ligand in the sample and ED-ligand conjugate for limiting the amount of antibody binding sites. The advantages of the CEDIA immunoassay system over conventional homogeneous EIA's include a linear dose response curve and lower limits of detection of analytes in human body fluids. The demonstrated sensitivity achievable with CEDIA technology suggests further applications on a wide range of analytes including vitamins, hormones, drugs and cancer markers. A new variant of CEDIA technology leading to a single liquid reagent immunoassay useful for on-site testing has also been developed.
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PMID:A new homogeneous enzyme immunoassay using recombinant enzyme fragments. 251 25

A sensitive and reproducible enzyme-linked immunosorbent assay (ELISA) has been developed using T cell hybridomas as coating antigen, for detection of Fc receptors for IgA (Fc alpha R). T-T hybridomas were generated from fusions of Fc alpha R+ T cell clones from mouse Peyer's patches with the Fc alpha R- R1.1 T lymphoma cell line. The 2 T-T hybridomas (designated Th HA) used here express Fc alpha R as determined by a rosette method and by ELISA. Th HA cells were cultured under conditions for maximum Fc alpha R expression, were added to individual wells of 96-well EIA plates, and were fixed in situ with glutaraldehyde. Plates were incubated with purified mouse monoclonal IgA, IgM or IgG1 and were developed with beta-galactosidase-coupled goat IgG antibodies specific for mouse heavy chains. Using the ELISA, both Th HA cell lines were shown to express significant levels of Fc alpha R, lower but detectable Fc mu R, and no discernible Fc gamma 1R. Interestingly, the rosette assay only allowed detection of receptors for IgA. When splenic lymphocytes were used, good Fc mu R and less Fc alpha R expression occurred on these cells as determined by ELISA and rosetting; however, no Fc gamma 1R cells were detected by either method. Thus, the ELISA is sensitive and reproducible, and allows an objective measurement of FcR expressed on T cells.
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PMID:An enzyme-linked immunosorbent assay (ELISA) for detection of Fc alpha receptors on isotype-specific T cells. 293 84

A double antibody sandwich immunoassay (EIA) was developed for the detection of Salmonella. The assay utilizes a beta-galactosidase-murine myeloma monoclonal antibody (M467) conjugate prepared with the heterobifunctional coupling reagent, N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP) and uses 4-methyl umbelliferyl beta-D-galactoside as a fluorogenic substrate for the enzyme. The EIA is sensitive and rapid, and compared favorably with the conventional cultural technique in the analysis of 60 feed samples naturally contaminated with Salmonella. Proteins or natural contaminants from the sample did not interfere in the assay.
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PMID:A fluorescent enzyme immunoassay for Salmonella detection. 328 71

We have developed simple methods for measuring recombinant human tumor necrosis factor alpha (rHu-TNF alpha) and antibodies to rHu-TNF alpha in the sera of animals intravenously injected with rHu-TNF alpha. rHu-TNF alpha was measured by a competitive binding enzyme immunoassay (C-EIA) using standard rHu-TNF alpha, beta-galactosidase labeled rHu-TNF alpha as enzyme-labeled antigen (E-Ag) and anti-rabbit IgG goat immunoglobulins coupled to bacterial cell walls (insolubilized second antibody). In contrast, anti-rHu-TNF alpha antibodies were measured by a sandwich EIA (S-EIA) using purified anti-rHu-TNF alpha rabbit IgG as standard, beta-galactosidase labeled rHu-TNF alpha as E-Ag, and rHu-TNF alpha coupled to bacterial cell walls as insolubilized antigen. C-EIA permits the determination of serum rHu-TNF alpha within the range of 2-150 U/ml (about 0.7-52 ng/ml) with a CV of below 7.6% and 99% recovery. S-EIA permits the determination of anti-rHu-TNF alpha antibodies within the range of 70-1000 ng/ml with a CV of less than 4% and 94.8-106.9% recovery.
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PMID:Simple enzyme immunoassay methods for recombinant human tumor necrosis factor alpha and its antibodies using a bacterial cell wall carrier. 328 46

Monoclonal mouse hybridoma antibodies were obtained for secreted cellular fibronectin (cFn) from A8387 fibrosarcoma cells. One of them, 52-DH1 (DH), reacted exclusively with cFns but not with plasma Fns (pFns) in immunoblotting and solid-phase EIA. The DH antibody also recognized thermolysin cFn fragments and beta-galactosidase-Fn fusion protein which contained the ED sequence specific to at least some forms of cFns. On the other hand, the DH antibody failed to recognize a fusion protein that was otherwise identical but lacked the ED sequence. Thus, the antigenic determinant for the DH antibody was located to the ED sequence. The DH antibody was then used to study the expression of ED sequence containing cFn (EcFn). For comparisons, another monoclonal antibody, 52BF12 (BF), recognizing equally well both pFns and cFns, was used. Immunoblotting of pFn fragments indicated that this antibody had the antigenic determinant at or close to the cell-binding site of Fn. EcFn was revealed by the DH antibody in embryonic and adult fibroblasts and in a variety of other cultured normal and malignant human cells. In embryonic tissues EcFn was abundant in developing basement membranes, as shown in foetal kidney and muscle, while in adult tissues it was confined only to endothelia of larger blood vessels. Furthermore, in embryonic tissues the capillaries showed bright EcFn-positivity not found any more in adult tissues. Human plasma contained a small quantity of EcFn, which may hence have an endothelial origin. EcFn was also prominent in the stroma of malignant tumours as well as in reactive benign conditions, such as granulation tissue and decidual cells. The results suggest that EcFn is a form of the protein which may have a particular role in developing and reactive tissues in embryos and adults.
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PMID:Differential expression of the ED sequence-containing form of cellular fibronectin in embryonic and adult human tissues. 350

Two antibodies were prepared for use in a sandwich enzyme immunoassay of human IgG. Completely purified guinea pig anti-human IgG was labelled with beta-D-galactosidase (EC 3.2.1.23), using a heterobifunctional cross-linker named GMBS. Partially purified anti-human IgG was immobilized on a new solid support: Amino-Dylark balls. Optimal conditions for immobilizing the antibody, using glutaraldehyde as the coupling reagent, were studied in detail. With the enzyme-labelled antibody and the solid-phase anti-human IgG, a sandwich enzyme immunoassay of human IgG with a lower limit of detection at 10.5 pM (0.3 ng/tube) was developed. A comparative study of the EIA method and a laser nephelometric method showed a good correlation. The specificity of the assay was excellent: all 4 types of IgG tested showed the maximum 0.0001%; human IgA, IgM and albumin possessed the maximum 0.54% in their cross-reactivity values with human IgG.
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PMID:A new solid support for sandwich enzyme immunoassays of human immunoglobulin G. 393 19

Spleen cells from Balb C mice immunized with purified Yu human myeloma IgE were fused with NS-1 mouse myeloma cells. After initial EIA screening for antibody-secreting cells, 20 hybrids were further characterized for cell growth, ascites production, antibody titer, specificity and affinity. Immunoglobulins purified from ascites fluid obtained from selected clones were labelled with beta-galactosidase. Combinations were made using either antibodies as capture and as conjugate against calibrated human IgE plasma samples. The combination of monoclonal anti IgE X b 10-22 as a capture antibody and X b 6-16 as a conjugate gave the best sensitivity and slope in EIA. It was successfully used in a sensitive two-step-enzyme-immunoassay for total IgE. The X b 6-16 conjugate was also assayed for the detection of allergen specific IgE antibodies. The results presented and discussed indicate that monoclonal antibodies could favourably substitute for polyclonal anti IgE antibodies in such assays.
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PMID:Monoclonal antibodies to human IgE: utilization for total IgE quantification and estimation of allergen specific IgE antibodies. 639 32

The performance of a competitive EIA for the detection of HIV-2-specific antibody utilising a viral lysate antigen was assessed over a 3 year period in The Gambia, West Africa, and compared with a commercially available assay, ELAVIA-2, using three panels of sera. An immunodominant region of the transmembrane glycoprotein of an HIV-2 isolate (ANT 53) was also cloned and expressed in E. coli as a beta-galactosidase fusion protein and the resulting recombinant protein substituted in place of the existing viral lysate antigen. Competitive EIAs were found to be both a specific and sensitive means of reliably determining the HIV-2 status of an individual with a high predictive value, particularly when a strategy of concordant positive results in the two EIAs was used. When either anti-HIV-2 competitive EIAs were used in conjunction with a competitive EIA for anti-HIV-1 detection it was possible in the vast majority of cases to identify the virus-type infecting an individual and speciate HIV-1 and HIV-2 infections. A few sera which showed similar regression profiles when diluted over a serial tenfold dilution steps were identified as possible dual infections.
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PMID:Competitive EIA for anti-HIV-2 detection in The Gambia: use as a screening assay and to identify possible dual infections. 848 35

Equine infectious anemia virus (EIAV) is a lentivirus in the retrovirus family of viruses. Replication-defective EIAV vectors have been constructed that encode bacterial puromycin-N-acetyl transferase and E. coli beta-galactosidase. These vectors could be prepared with titers greater than 10(5) infectious units/ml and were able to act as vehicles to carry genes into cultured human cells. In addition, stable helper cell lines were created by modifying human 293 cells to express EIAV proteins. Unlike retroviral vectors based on murine leukemia virus, EIAV lentiviral vectors transduce nondividing (aphidicolin-arrested) cells. These properties make EIAV vectors promising gene transfer vehicles.
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PMID:Gene transfer vectors derived from equine infectious anemia virus. 993 Mar 1


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