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)

In this study, we provide evidence that a recombinant fusion protein containing beta-galactosidase and a tandem repeat peptide of immunogenic dominant epitope of foot-and-mouth disease virus (FMDV) VP1 protein elicits high levels of neutralizing antibody and protects both guinea pigs and swine against infection. Vaccination with this fusion protein induced a FMDV-specific proliferative T-cell response and a neutralizing antibody response. The immunized guinea pigs and swine were protected against FMD type O virus infection. Two DNA plasmids expressing genes of foot-and-mouth disease were constructed. Both plasmids pBO1 and pCO1 contain a signal sequence of the swine immunoglobulin G (IgG) gene and fusion protein gene of pXZ84. The signal sequence and fusion protein gene were under the control of a metallothionein promoter in the case of the pBO1 plasmid and under the control of a cytomegalovirus immediate early promoter in the case of pCO1 plasmid. When pBO1 and pCO1 were inoculated intramuscularly into guinea pigs, both plasmids elicited a neutralizing antibody response and spleen cell proliferation increased following stimulation with FMDV antigen, but animals were not protected from viral challenge.
 ...
PMID:Recombinant fusion protein and DNA vaccines against foot and mouth disease virus infection in guinea pig and swine. 1033 37

The antigenic properties of a viral peptide from the surface of foot-and-mouth disease virus particles have been successfully mimicked by multiple insertion in solvent-exposed regions of Escherichia coli beta-galactosidase. By increasing the number of viral peptides per enzyme monomer, the average IC(50) of hybrid proteins in a competitive enzyme-linked immunosorbent assay) have decreased to values close to that presented by natural virions. Moreover, the antigenic diversity of these new recombinant enzymes when measured with different anti-virus antibodies has also been largely reduced, indicating a better presentation of the epitopes located in the viral peptide. Although bivalent antibody binding could have been favoured by multiple presentation, conformational modifications of the viral peptide, due to the presence of other insertions or a cooperative antibody binding cannot be excluded. In addition, a multidimensional antigenic analysis have grouped together the multiple-inserted proteins with the native virus, suggesting that increasing the number of insertions could be a good strategy to reproduce the antigenic properties of an immunoreactive peptide in a natural multimeric disposition.
 ...
PMID:Successful mimicry of a complex viral antigen by multiple peptide insertions in a carrier protein. 1082 57

Peptide display on solvent-exposed surfaces of engineered enzymes allows them to respond to anti-peptide antibodies by detectable changes in their enzymatic activity, offering a new principle for biosensor development. In this work, we show that multiple peptide insertion in the vicinity of the Escherichia coli beta-galactosidase active site dramatically increases the enzyme responsiveness to specific anti-peptide antibodies. The modified enzymes HD7872A and HT7278CA, carrying eight and 12 copies respectively of a foot-and-mouth disease peptide per enzyme molecule, show antibody-mediated activation factors higher than those previously observed in the first generation enzymatic sensors, for HT7278CA being close to 400%. The analysis of the signal transduction process with multiple inserted proteins strongly suggests a new, non-exclusive mechanism of enzymatic regulation in which the target proteins might be stabilised by the bound antibody, extending the enzyme half-life and consequently enhancing the signal-background ratio. In addition, the tested sensors are differently responsive to sera from immune farm animals, depending on the antigenic similarity between the B-cell epitopes in the immunising virus and those in the peptide used as sensing element on the enzyme surface. Altogether, these results point out the utility of these enzymatic biosensors for a simple diagnosis of foot-and-mouth disease in an extremely fast homogeneous assay.
 ...
PMID:Enhanced response to antibody binding in engineered beta-galactosidase enzymatic sensors. 1200 3

In this study, the sequences of capsid protein VPI regions of YNAs1.1 and YNAs1.2 isolates of foot-and-mouth disease virus (FMDV) were analyzed and a peptide containing amino acids (aa) 133-158 of VP1 and aa 20-34 of VP4 of FMDV type Asia I was assumed to contain B and T cell epitopes, because it is hypervariable and includes a cell attachment site RGD located in the G-H loop. The DNA fragments encoding aa 133-158 of VP1 and aa 20-34 of VP4 of FMDV type Asia 1 were chemically synthesized and ligated into a tandem repeat of aa 133-158-20 approximately 34-133-158. In order to enhance its immunogenicity, the tandem repeat was inserted downstream of the beta-galactosidase gene in the expression vector pWR590. This insertion yielded a recombinant expression vector pAS1 encoding the fusion protein. The latter reacted with sera from FMDV type Asia 1-infected animals in vitro and elicited high levels of neutralizing antibodies in guinea pigs. The T cell proliferation in immunized animals increased following stimulation with the fusion protein. It is reported for the first time that a recombinant fusion protein vaccine was produced using B and T cell epitopes of FMDV type Asia 1 and that this fusion protein was immunogenic. The fusion protein reported here can serve as a candidate of fusion epitopes for design of a vaccine against FMDV type Asia 1.
 ...
PMID:Immunogenicity of a recombinant fusion protein of tandem repeat epitopes of foot-and-mouth disease virus type Asia 1 for guinea pigs. 1219 4

Protein engineering allows the generation of hybrid polypeptides with functional domains from different origins and therefore exhibiting new biological properties. We have explored several permissive sites in Escherichia coli beta-galactosidase to generate functional hybrid enzymes displaying a mouse scFv antibody fragment. When this segment was placed at the amino-terminus of the enzyme, the whole fusion protein was stable, maintained its specific activity and interacted specifically with the target antigen, a main antigenic determinant of foot-and-mouth disease virus. In addition, the antigen-targeted enzyme was enzymatically active when bound to the antigen and therefore useful as a reagent in single-step immunoassays. These results prove the flexibility of E. coli beta-galactosidase as a carrier for large-sized functional domains with binding properties and prompt the further exploration of the biotechnological applicability of the scFv enzyme targeting principle for diagnosis or other biomedical applications involving antigen tagging.
 ...
PMID:Engineering of Escherichia coli beta-galactosidase for solvent display of a functional scFv antibody fragment. 1250 69

Yersinia ruckeri, the etiological agent of the enteric red mouth disease (ERM) of salmonids, produces Yrp1, a serralysin metalloprotease involved in pathogenesis. We describe here the hydrolytic and immunogenic properties of Yrp1. The protease was able to hydrolyze different matrix and muscle proteins as laminin, fibrinogen, gelatine, actin, and myosin but not type II and IV collagens. In addition, the Yrp1 protein, when inactivated by heat and used as an immunogen, was able to elicit a strong protection against the development of ERM. The analysis of different Y. ruckeri strains with (Azo+) or without (Azo-) Yrp1 activity showed that all of them contained the yrp1 operon. By using yrp1::lacZ operon fusions, protease production analysis, and complementation studies, it was possible to show that an Azo- strain was blocked at the transcription level. The transcriptional study of the yrp1 operon under different environmental conditions showed that it was regulated by osmolarity and temperature, without pH influence. Finally, when beta-galactosidase activity was used as a probe in vivo, the progression of the disease in the fish could be visualized, and the tropism of the bacterium and affected organs could be defined. This system opens a vast field of study not only with regard to fish disease progression but also in pathogen interactions, temporal gene expression, carrier stages, antibiotic resistance selection, etc.
 ...
PMID:In vitro and in vivo studies of the Yrp1 protease from Yersinia ruckeri and its role in protective immunity against enteric red mouth disease of salmonids. 1466 Mar 82

Previously, we demonstrated that a fusion protein (Gal-FMDV) consisting of beta-galactosidase and an immunogenic peptide, amino acids (141-160)-(21-40)-(141-160), of foot-and-mouth disease virus (FMDV) VP1 protein induced protective immune responses in guinea pigs and swine. We now designed a new potential recombinant protein vaccine against FMDV in swine. The immunogenic peptide, amino acids (141-160)-(21-40)-(141-160) from the VP1 protein of serotype O FMDV, was fused to the carboxy terminus of a swine immunoglobulin G single heavy chain constant region and expressed in Escherichia coli. The expressed fusion protein (IgG-FMDV) was purified and emulsified with oil adjuvant. Vaccination twice at an interval of 3 weeks with the emulsified IgG-FMDV fusion protein induced an FMDV-specific spleen proliferative T-cell response in guinea pigs and elicited high levels of neutralizing antibody in guinea pigs and swine. All of the immunized animals were efficiently protected against FMDV challenge. There was no significant difference between IgG-FMDV and Gal-FMDV in eliciting immunity after vaccination twice in swine. However, when evaluating the efficacy of a single inoculation of the fusion proteins, we found that IgG-FMDV could elicit a protective immune response in swine, while Gal-FMDV only elicited a weak neutralizing activity and could not protect the swine against FMDV challenge. Our results suggest that the IgG-FMDV fusion protein is a promising vaccine candidate for FMD in swine.
 ...
PMID:Comparison of immune responses against foot-and-mouth disease virus induced by fusion proteins using the swine IgG heavy chain constant region or beta-galactosidase as a carrier of immunogenic epitopes. 1546 47


<< Previous 1 2 3