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Biomedical subjects

D Portetelle

Publications and source records attributed to D Portetelle.

At least 127 records · Page 7Linked to original sources
PubMed1985

Immunological and structural relatedness of catabolic ornithine carbamoyltransferases and the anabolic enzymes of enterobacteria.

Purified catabolic ornithine carbamoyltransferase of Pseudomonas putida and anabolic ornithine carbamoyltransferase (argF product) of Escherichia coli K-12 were used to prepare antisera. The two specific antisera gave heterologous cross-reactions of various intensities with bacterial catabolic ornithine carbamoyltransferases formed by Pseudomonas and representative organisms of other bacterial genera. The immunological cross-reactivity observed only between the catabolic ornithine carbamoyltransferases and the anabolic enzymes of enterobacteria suggests that these proteins share some structural similarities. Indeed, the amino acid composition of the anabolic ornithine carbamoyltransferase of E. coli K-12 (argF and argI products) closely resembles the amino acid compositions of the catabolic enzymes of Pseudomonas putida, Aeromonas formicans, Streptococcus faecalis, and Bacillus licheniformis. Comparison of the N-terminal amino acid sequence of the E. coli anabolic ornithine carbamoyltransferase with that of the A. formicans and Pseudomonas putida catabolic enzymes shows, respectively, 45 and 28% identity between the compared positions; the A. formicans sequence reveals 53% identity with the Pseudomonas putida sequence. These results favor the conclusion that anabolic ornithine carbamoyltransferases of enterobacteria and catabolic ornithine carbamoyltransferases derive from a common ancestral gene.

Amino Acid Sequence↗
PubMed1984

Biologically active epitopes of bovine leukemia virus glycoprotein gp51: their dependence on protein glycosylation and genetic variability.

A panel of monoclonal antibodies to the bovine leukemia virus envelope glycoprotein (BLV gp51) has previously demonstrated the association of the biological activities of the virus (infectivity, syncytia induction) with three out of eight epitopes of gp51. In BLV-infected cells, the unglycosylated homolog of the precursor to the BLV envelope glycoproteins (gPr72env) is a 47,000-MW polypeptide. Immunoprecipitation studies with monoclonal antibodies show that the neutralizing antibody-inducing sites, although present in gPr72env, are not conserved in the 47,000-MW unglycosylated homolog. Finally, it is demonstrated that the neutralizing antibody-inducing sites of gp51 are subject to antigenic variation among BLV isolates of the same or different geographical origins.

Animals↗
PubMed1984

Bovine leukemia virus (BLV)--a structural model based on chemical crosslinking studies.

Nearest neighbor relationships between lipid and protein as well as between high-molecular-weight viral RNA and protein were investigated in bovine leukemia virus (BLV) particles using chemical crosslinking reagents. Separation of dimethyl suberimidate (DMS) induced lipid-protein complexes by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the phosphoprotein pp 15 is linked to the lipid bilayer of the virus. By use of diepoxybutan (DEB) as crosslinking reagent p 12 and again pp 15 were found to be linked to the viral RNA. Based on these results and our previous data describing the spatial relationships of major structural proteins within BLV particles, a structural model of BLV is proposed.

Animals↗
PubMed1984

Experimental infection of sheep and goat with bovine leukemia virus: localization of proviral information on the target cells.

Bovine leukemia virus (BLV) proviral integration was studied in the DNA from circulating leucocytes or tumor cells of sheep and goats experimentally infected with BLV. Southern blot analysis of infected cell DNA for BLV proviral sequences indicate that: (1) the provirus may be found as unintegrated molecules in the circulating leucocytes of infected sheep; (2) the provirus is integrated at many sites in the genome of the leucocytes of infected goats and occasionally in infected sheep; (3) the provirus is present at only a few sites in the DNA of sheep or goat tumor cell clones. A second case of goat lymphosarcoma is also reported.

Animals↗
PubMed1984

Epitopes of bovine leukemia virus glycoprotein gp51 recognized by sera of infected cattle and sheep.

Sera of BLV-infected cattle and sheep are tested for their reactivity with different gp51 subregions by competition with radiolabeled monoclonal antibodies directed against 8 different gp51 epitopes. Sheep antisera are found to be very polyvalent, since they are able to displace the fixation of any of the mouse monoclonal antibodies to gp51. Bovine antisera do not display significant competition with monoclonal antibodies direct against 5 out of 8 gp51 epitopes. The bovine antibody response to gp51 is focused to a limited subregion of this molecule, bearing 3 epitopes (F, G and H) recognized by antibodies with virus-neutralizing activity. The differential reactivity of cattle and sheep antisera to BLV gp51 is discussed in relation to the pathology of BLV infection in these two species.

Animals↗
PubMed1984

Ultrastructural demonstration of retrovirus antigens with immuno-gold staining in prodromal acquired immune deficiency syndrome.

The peripheral lymphocytes of a patient with prodromal acquired immune deficiency syndrome contained giant multivesicular bodies. These were specifically stained by immuno-gold labelled polyclonal antibodies against the major core protein p24 of bovine leukaemia virus and human T cell leukaemia virus I. Moreover, the patient's serum was positive for bovine leukaemia virus by the ELISA method.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Isolation and purification of bovine immunoglobulins: use of Sephacryl S-300 filtration avoids protein precipitation steps.

A simplified purification method for bovine IgG1, IgG2, IgM, IgA and S-IgA is presented. It takes advantage of Sephacryl S-300 gel filtration. When applied to this column, colostral whey can be separated into IgM, S-IgA and IgG rich fractions. Filtration of blood serum leads to IgM, IgA and IgG rich fractions. IgM, IgG1, IgG2, S-IgA and IgA are then further purified by anion exchange chromatography.

Acrylic Resins↗
PubMed1984

[Oncogenes].

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Animals↗
PubMed1983

Solid-phase enzyme immunoassay of urokinase using monoclonal antibodies.

Using two monoclonal antibodies directed against urokinase, we have developed a micro enzyme-linked immunosorbant assay (ELISA) to detect and measure urokinase in biological fluids. The system presents the following characteristics: simple and rapid procedure, reproducibility, sensitivity (urokinase levels down to 1 ng/ml) and evaluation of the enzyme in biological fluids such as urine, pleural effusions, and ascitic fluids without preliminary purification.

Antibodies, Monoclonal↗
PubMed1983

Use of monoclonal antibody in an ELISA test for the detection of antibodies to bovine leukaemia virus.

A variant of the ELISA technique, involving a monoclonal anti-gp51 antibody yields a highly sensitive method for the detection of bovine leukaemia virus (BLV) antibodies. The gp51 antigen-coated microtitre plates are obtained by incubation of plastic-adsorbed monoclonal antibodies with a non-purified mixture of BLV antigens. Sera to be tested are incubated in the wells of the gp51-coated plates and bound antibodies are revealed by an enzyme-linked antibovine immunoglobulin reagent. This test is as sensitive as liquid phase radioimmunoassay using the same gp51 antigen and thus appears as a highly sensitive, practical, rapid and cheap method for the detection of BLV antibodies.

Animals↗