Search results for "PLASMID"
showing 10 items of 327 documents
A hantavirus nucleocapsid protein segment exposed on hepatitis B virus core particles is highly immunogenic in mice when applied without adjuvants or…
2005
Hepatitis B virus (HBV) core particles carrying the amino-terminal 120 amino acids (aa) of the nucleocapsid (N) protein of the hantaviruses Dobrava, Hantaan or Puumala have been demonstrated to be highly immunogenic in mice when complexed with adjuvants. Here we demonstrate that even without adjuvant, these chimeric particles induced high-titered, and strongly cross-reactive N-specific antibody responses in BALB/c and C57BL/6 mice. The induced N-specific antibodies represented all IgG subclasses. Pre-existing core-specific antibodies did not abrogate the induction of an N-specific immune response by a hantavirus N insert presented on core particles. Therefore, chimeric core particles should…
The yeast inositol monophosphatase is a lithium- and sodium-sensitive enzyme encoded by a non-essential gene pair
1999
Inositol monophosphatases (IMPases) are lithium-sensitive enzymes that participate in the inositol cycle of calcium signalling and in inositol biosynthesis. Two open reading frames (YHR046c and YDR287w) with homology to animal and plant IMPases are present in the yeast genome. The two recombinant purified proteins were shown to catalyse inositol-1-phosphate hydrolysis sensitive to lithium and sodium. A double gene disruption had no apparent growth defect and was not auxotroph for inositol. Therefore, lithium effects in yeast cannot be explained by inhibition of IMPases and inositol depletion, as suggested for animal systems. Overexpression of yeast IMPases increased lithium and sodium toler…
Assembly of fluorescent chimeric virus-like particles of canine parvovirus in insect cells
2004
Canine parvovirus (CPV) is a small non-enveloped ssDNA virus composed of the viral proteins VP1, VP2, and VP3 with a T=1 icosahedral symmetry. VP2 is nested in VP1 and the two proteins are produced by differential splicing of a primary transcript of the right ORF of the viral genome. The VP2 protein can be further proteolytically cleaved to form VP3. Previous studies have shown that VP1 and VP3 are unnecessary for capsid formation and consequently, that VP2 alone is sufficient for assembly. We have hypothesized that insertion of the enhanced green fluorescent protein (EGFP) at the N-terminus of VP2 could be carried out without altering assembly. To investigate the possibility to develop flu…
Instability of plasmid-encoded citrate permease in Leuconostoc
1996
M. KIHAL, H. PREVOST, M.E. LHOTTE, D.Q. HUANG AND C. DIVIES. 1996. The conversion from citrate positive (Cit+) to citrate negative (Cit-) phenotype of six strains of Leuconostoc mesetiteroides was followed during growth in milk and buffered or unbuffered MRS medium at 30 or 37°C. High rate of loss of Cit+ phenotype was observed. The Cit- phenotype was found to be linked to the loss of 22 to 23 kb plasmids. All Cit- mutants isolated from Leuc. mesenteroides subsp. cremoris 195 reverted spontaneously to the Cit+ phenotype. Hybridization experiments using a 0.8 kb fragment of the citP gene of Leuc. mesenteroides showed that all the plasmids which were lost in Cit- mutants encoded for a citrate…
Putative p24 complexes in Arabidopsis contain members of the delta and beta subfamilies and cycle in the early secretory pathway
2013
p24 proteins are a family of type I membrane proteins localized to compartments of the early secretory pathway and to coat protein I (COPI)- and COPII-coated vesicles. They can be classified, by sequence homology, into four subfamilies, named p24α, p24β, p24γ, and p24δ. In contrast to animals and fungi, plants contain only members of the p24β and p24δ subfamilies, the latter probably including two different subclasses. It has previously been shown that transiently expressed red fluorescent protein (RFP)-p24δ5 (p24δ1 subclass) localizes to the endoplasmic reticulum (ER) at steady state as a consequence of highly efficient COPI-based recycling from the Golgi apparatus. It is now shown that tr…
Isolation and purification of plasmids from Bacteroides fragilis using rubidium trichloroacetate density gradient centrifugation.
1983
A rapid and easy final purification method is described for the isolation of plasmids from B. fragilis. Using RbTCA density gradient centrifugation in an airfuge ultracentrifuge ccc plasmid DNA can be separated from RNA, residual chromosomal DNA, linear and oc plasmid DNA. Pure ccc plasmid DNA is obtained from cultures of between 1 ml and 2 l in less than one day.
Fast, non-toxic, and inexpensive n-butanol preparation of recombinant plasmids
2000
Various commercial and non-commercial plasmid preparation protocols are currently available. However, the kits are expensive and many of the protocols contain toxic chemicals. Here we present a novel, optimized and, therefore, very advantageous plasmid preparation protocol using n-butanol. The preparation can be performed quickly and no toxic chemicals are used, at overall costs of about one cent per plasmid preparation.Atualmente vários protocolos comerciais e não comerciais para preparação de plasmídeos estão disponíveis. Contudo, os kits são caros e muitos dos protocolos contêm substâncias químicas tóxicas. Apresentamos neste trabalho um novo, otimizado e portanto muito vantajoso protoco…
Multi-plasmid clash in a bacterial community: plasmid viability depends on the ecological setting of hosts
2021
AbstractPlasmids are genetic elements that disperse horizontally between different strains and species of bacteria and a major factor in the dissemination of virulence factors and antibiotic resistance. Understanding the ecology of plasmids has a notable anthropocentric value and therefore the interactions between bacterial hosts and individual plasmids have been studied in detail. However, bacterial systems often carry multiple genetically distinct plasmids, but dynamics of these multiplasmid “clashes” has remained unstudied. Here, we set to investigate the survival of 11 mobilizable or conjugative plasmids in five different ecological settings. The key incentive was to determine whether p…
Insect Cells for Heterologous Production of Recombinant Proteins
2010
Heterologous gene expression has become an indispensable and powerful tool for the production and subsequent functional analysis of proteins that are difficult to purify from their natural sources. Furthermore, it is the method of choice for the production of variants by introducing site-specific mutations into the DNA encoding the protein of interest. However, many systems are biased by disadvantages. The inability of bacteria to confer important post-translational modifications often results in functional failure of the recombinant protein. In addition, disulfide bonds are not formed properly in bacterial systems. Mammalian cells on the other hand modify properly, but they generally provi…