Search results for "acrylamide"
showing 10 items of 485 documents
Differential expression and interaction with the visual G-protein transducin of centrin isoforms in mammalian photoreceptor cells.
2004
Photoisomerization of rhodopsin activates a heterotrimeric G-protein cascade leading to closure of cGMP-gated channels and hyperpolarization of photoreceptor cells. Massive translocation of the visual G-protein transducin, Gt, between subcellular compartments contributes to long term adaptation of photoreceptor cells. Ca(2+)-triggered assembly of a centrin-transducin complex in the connecting cilium of photoreceptor cells may regulate these transducin translocations. Here we demonstrate expression of all four known, closely related centrin isoforms in the mammalian retina. Interaction assays revealed binding potential of the four centrin isoforms to Gtbetagamma heterodimers. High affinity b…
Evaluation of reverse transcription and polymerase chain reaction (RT/PCR) for the detection of rotaviruses: applications of the assay.
1996
Summary Our aim was to evaluate the reverse transcription and polymerase chain reaction (RT/PCR) technique for the detection of rotavirus shedding by infected children as a routine diagnostic procedure, in comparison to the enzyme-linked immunosorbent assay (ELISA), electron microscopy (EM) and polyacrylamide gel etectrophoresis (PAGE) of rotavirus double stranded RNA. Two-hundred and twenty stool specimens were collected from infants and young children with diarrhoea, and 10–20% faecal suspensions were made. Several methods of rotavirus dsRNA extraction were assayed. Electrophoretic analysis of viral RNA was carried out on 10% polyacrylamide gols followed by silver staining. RT/PCR was per…
In vitro reconstitution of rotavirus transcriptional activity using viral cores and recombinant baculovirus expressed VP 6
1993
International audience; Purified baculovirus-expressed group A rotavirus VP6 polypeptide was shown to be active in the recovery of the transcriptase activity associated with the reconstitution of the single-shelled rotavirus particle. Recombinant VP6 polypeptide was able to restore the transcriptional activity in purified viral cores from both SA-11 and RF rotavirus strains. Recombinant group C VP 6 (Cowden strain) is capable of binding as a trimer to group A viral core particles but unable to restore the transcriptase activity, suggesting that the binding of the polypeptide to cores is not the only requirement to restore the transcriptase activity. The VP 6 group A polypeptide was shown to…
Direct Identification of Each Specific Mutation in Codon 12 and 13 of ci-ki-ras2 by SSCP Analysis
1998
We compared the SSCP behaviour of the DNA fragments containing c-ki-ras 2 wild type 12 and 13 codons or each of the 12 possible point mutated sequences in these two codons. We found that a single electrophoresis condition was sufficient to distinguish each specific mutation from the other 11 and from the wild type sequence. This observation makes it possible to identify each specific mutation directly by SSCP without any need for reamplification and sequencing.
Site specificity of pea histone acetyltransferase B in vitro.
1993
Histone acetyltransferase B from pea embryonic axes has been purified approximately 300-fold by a combination of chromatographic procedures, including affinity chromatography on histone-agarose. The enzyme preparation has been used for the in vitro transfer of acetyl groups from [1-14C]acetyl-CoA to non-acetylated pea histone H4. Up to three acetyl groups can be introduced into the histone. The resulting mono-, di-, and triacetylated H4 isoforms were separated and sequenced to determine the acetylated sites. Only sites 5, 12, and 16 were used by histone acetyltransferase B, but no clear preference among them was observed. The absence of modification of other potentially acetylatable sites i…
The ATC1 gene encodes a cell wall-linked acid trehalase required for growth on trehalose in Candida albicans.
2004
After screening a Candida albicans genome data base, the product of an open reading frame (IPF 19760/CA2574) with 41% identity to Saccharomyces cerevisiae vacuolar acid trehalase (Ath1p) was identified and named Atc1p. The deduced amino acid sequence shows that Atc1p contains an N-terminal hydrophobic signal peptide and 20 potential sites for N-glycosylation. C. albicans homozygous mutants that lack acid trehalase activity were constructed by gene disruption at the two ATC chromosomal alleles. Analysis of these null mutants shows that Atc1p is localized in the cell wall and is required for growth on trehalose as a carbon source. An Atc1p endowed with acid trehalase activity was obtained by …
In vitro studies of adsorption of milk proteins onto tooth enamel
2006
Abstract The aim of this investigation was to study in vitro adsorption of milk proteins onto tooth enamel. In vitro “milk protein pellicles” were formed on enamel specimens incubated in fluid milk products: skimmed milk (pH 6.7), acidified skimmed milk (pH 4.2), yoghurt and neutralized yoghurt (pH 6.7). The enamel specimens were used as such or pre-incubated in saliva. The “milk pellicles” were desorbed from enamel surfaces, and proteins separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Proteins were identified by their pattern of migration in SDS-PAGE or by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) fingerp…
Safety Evaluation of Food contact paper and board using Chemical Tests and in vitro Bioassays-The role of known and unknown substances
2010
International audience; In vitro toxicological tests has have been proposed as an approach to complement the chemical safety assessment of food contact materials, particularly those with a complex or unknown chemical composition such as paper and board. An EU 5th framework program project “BIOSAFEPAPER – Application of bioassays for safety assessment of paper and board for food contact” specially focused on the application of biotests to paper and board. The project included both chemical characterization and toxicological testing of a representative number of paper and board extracts prepared according to the proposed end use (wet, fatty and dry food contact). Among the concerns addressed …
Increase of sensitivity and validity of the SOS/umu-test after replacement of the beta-galactosidase reporter gene with luciferase.
1998
The SOS/umu-test with Salmonella typhimurium TA1535/pSK1002 as tester strain is a rapid and valuable bacterial assay for screening of umuC-dependent mutagenic potential of chemical compounds and chemicals relevant to environmental pollution. The initial assay was modified by replacing the beta-galactosidase reporter gene with luciferase. Thereby, the sensitivity of the umu-test was increased significantly and the susceptibility to intensively coloured solutions was reduced. The alternative enzyme assay in the modified umu-test (umu-Luc) represents an independent method which allows to confirm the colorimetric results obtained with the original SOS/umu-test system (umu-Gal) by measuring the …
Localization of HSP70, Cdc2, and cyclin B in sea urchin oocytes in non-stressed conditions.
2003
In Paracentrotus lividus embryos, a Mediterranean sea urchin species, HSP70 is present in all the cells. During cell division it localizes under normal growth conditions on the centrosomes and on the whole isolated mitotic apparatus. Now, in situ hybridization, Western blot analyses, and immunohistochemistry show that the HSP70 mRNA is present in both small and large P. lividus oocytes, that all four isoforms of HSP70 can be found also in the oocytes, and that a certain amount of HSP70 localizes on asters and spindles during polar body formation. Moreover, two representative cell-cycle related proteins, cyclin B, and Cdc2, are present both in small and large oocytes, concentrating in the ge…