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

A highly antigenic polypeptide fragment of the recombinant Echinococcus multilocularis antigen II/3 was produced in Escherichia coli and purified for application in enzyme-linked immunosorbent assay (ELISA). The antigen II/3-encoding 1.0 kb DNA sequence was reduced by sonication into smaller DNA fragments which were subsequently cloned into lambda gt11. Three clones could be isolated from the sublibrary, all synthesizing a recombinant antigen as a stable beta-galactosidase fusion protein. In a further step, the 0.6-kb insert from one positive clone was subcloned into the plasmid pAR 3038, which directed efficient synthesis of the antigen fused to only 11 amino acids from the N-terminus of the phage T7 major capsid protein. The plasmid-encoded antigen (antigen II/3-10) was purified from a bacterial cell extract and then tested in an ELISA. Using sera from 88 patients with an E. multilocularis-infection, a high diagnostic sensitivity of 90% was demonstrated. Investigation of sera from 220 patients with various helminthic infections showed a specificity of 99%, suggesting the suitability of the antigen II/3-10 as an immunodiagnostic tool.
 ...
PMID:Application of a recombinant Echinococcus multilocularis antigen in an enzyme-linked immunosorbent assay for immunodiagnosis of human alveolar echinococcosis. 267 25

A Taenia crassiceps metacestode cDNA expression library in lambda gt 11 was screened with rabbit antisera to metacestodal T. solium and T. saginata crude extract. Primary clones (121) were identified, and after rescreening and lysogenization in Escherichia coli Y 1089, were tested in Western blot for reactivity with the same antisera. In addition, analyses were performed with rabbit antisera directed towards T. crassiceps and Echinococcus granulosus metacestode crude extract, sera from humans with neurocysticercosis (Mexico) and other important helminth diseases, mice and calves with experimental T. crassiceps and T. saginata infections and normal sera. Of those tested, 22 clones expressing beta-galactosidase fusion proteins (approximately 118-132 kDa) were reactive with IgG antibodies of cysticercotic patients and T. crassiceps infected mice. Of these clones, 11 were also sero-positive with calf-IgG antibodies against T. saginata larvae. None of the 22 clones reacted with IgG antibodies due to human cystic and alveolar echinococcosis, intestinal/hepatic or urinary schistosomiasis, African onchocerciasis or with sera from uninfected controls (man, rabbit, calf and mouse). Of these 22 clones, 15 have been subcloned into the plasmid vectors pGEX-2T (modified) and pT7T3 alpha 19. Expressed glutathione-S-transferase fusion proteins were again tested for sensitivity and specificity by Western blot, and concentrated by affinity chromatography. The nucleotide sequence of the cDNA inserts of 9 clones has been determined in pT7T3 alpha 19 and revealed identity in 4 and 5 clones, respectively.
 ...
PMID:Preparation and sequence analysis of Taenia crassiceps metacestode recombinant antigens with potential for specific immunodiagnosis of human cerebral cysticercosis. 771 96

Coproantigen ELISA based tests for diagnosis of canine echinococcosis provide high specificity and sensitivity. However, the antigenic molecules present in faeces from infected dogs have not yet been characterised. While initial attempts to determine the molecular weights of Echinococcus granulosus coproantigens by SDS-PAGE and Western blotting with coproantigen reactive capture antibodies were equivocal, they suggested presence of a significant carbohydrate component. Periodate treatment of coproantigen positive faecal supernatants resulted in a significant reduction (53%) in ELISA activity, suggesting that carbohydrates are involved in the antigenic structure of E. granulosus coproantigens. Protease treatment of antigenic molecules resulted in an 11% reduction in absorbance in ELISA, indicating that protein components were also present which affected by enzyme activity. Lectin-binding ELISA assays indicated strong affinity of E. granulosus coproantigens to concanavalin agglutinin and Lens culinaris agglutinin, and moderate binding to wheat-germ agglutinin and peanut agglutinin. No binding was detectable to Ulex europaensis agglutinin-I, Bandeiraea simplicifolia or Dolichos biflorus agglutinin. These data indicate that E. granulosus coproantigens from infected dog faeces possibly contained alpha-D-mannose and/or alpha-D-glucose, beta-galactose and N-acetyl-beta-glucosamine residues. To verify the role of carbohydrate moieties in coproantigens, faecal samples were treated with exoglycosidase and tested in the coproantigen ELISA. Treatment with beta-galactosidase or N-acetyl-beta-glucosamine reduced ELISA activity by 44 and 30%, respectively. Incubation with a panel of other specific exoglycosidases including alpha-galactosidase as well as alpha-L-fucosidase, alpha-mannosidase, beta-mannosidase, alpha-glucosidase, beta-glucosidase, beta- fructosidase, or neuraminidase, did not alter coproantigen detection in ELISA. The results indicate that coproantigens present in faeces from E. granulosus naturally infected dogs were highly glycosylated and contain beta- galactose and N-acetyl-beta-glucosamine. The putative relationship of antigenic molecules with the tapeworm glycocalyx is discussed.
 ...
PMID:Partial characterisation of carbohydrate-rich Echinococcus granulosus coproantigens. 1457 18