Search results for "Thermolabile"

Sensitivity and Specificity of Reiter Protein Complement-Fixation (RPCF) Test for Syphilis1

1957

D'Alessandro and his co-workers reported on the separation of four different fractions from the Reiter strain of Treponema pallidum (1, 2, 3). This report deals with the thermolabile soluble protein extract of the Reiter treponeme. The antigen employed in this study was prepared by de Bruijn (4) using the technic described by D'Alessandro. The antigen is prepared briefly as follows: The Reiter treponemes are grown in a Brewer thioglycollate medium. After harvesting the washing, the treponemes are subjected to cryolysis. The lysate is dialyzed against increasing concentrations of ammonium sulfate. The precipitate thus obtained is dissolved in a veronal-buffered saline. This solution is dialy…

1986

The terpolymerization of the three monomers (3-vinyl phenylazo)methylmalodinitrile (1), (3-vinyl phenylazo)phenylsulfid (2) or 1-(3-vinylphenylazo)-1,1′-diphenyl methylacetate (3) with methyl methacrylate and butanediol-1,4-dimethyacrylate leads to networks in which the thermolabile azo groups remain intact. Both, the azo monomer and the crosslinking agent are essentially quantitatively incorporated into the network before the conversion of the third monomer is complete. The networks have been characterized in terms of their swelling in benzene, chlorobenzene, and methacrylonitrile. Die Terpolymerisation der drei Monomeren (3-Vinylphenylazo)-methylmalodinitril (1), (3-Vinylphenylazo)phenyls…

Caseicin, a bacteriocin from Lactobacillus casei.

1993

The intracellular bacteriocin caseicin 80 was purified from cell extracts of Lactobacillus casei strain B80. It is a thermolabile protein with an apparent molar mass of 42 kDa. As no plasmids were observed in the bacteriocinogenic strain it is assumed that caseicin is encoded by the bacterial chromosome. Using 14C-labelled precursors it was found that biosynthesis of DNA and proteins was influenced by caseicin but this inhibition is probably not the primary effect. The incorporation of fructose but not of glucose into cellular material was inhibited by caseicin.

A Lipopolysaccharide Antigen of the Treponema

1958

IMMUNOCHEMICAL studies carried out by D'Alessandro et al. 1 on a non-pathogenic, culturable treponeme, the so-called Reiter treponeme, revealed the presence of four antigenic components: (1) a thermolabile protein; (2) a specific, thermostable antigen with polysaccharide characteristics; (3) a lipoid, corresponding to the ubiquitous lipidic antigen cardiolipin; (4) another lipoid similar to the organ-specific cerebral antigen of Witebsky2. These studies led to the conclusion that the treponemes, like other organisms, are mosaics of antigens, and a safe basis was established for a better understanding of the complex serological response of the infected host.

Targeting Cavity-Creating p53 Cancer Mutations with Small-Molecule Stabilizers: the Y220X Paradigm

2020

We have previously shown that the thermolabile, cavity-creating p53 cancer mutant Y220C can be reactivated by small-molecule stabilizers. In our ongoing efforts to unearth druggable variants of the p53 mutome, we have now analyzed the effects of other cancer-associated mutations at codon 220 on the structure, stability, and dynamics of the p53 DNA-binding domain (DBD). We found that the oncogenic Y220H, Y220N, and Y220S mutations are also highly destabilizing, suggesting that they are largely unfolded under physiological conditions. A high-resolution crystal structure of the Y220S mutant DBD revealed a mutation-induced surface crevice similar to that of Y220C, whereas the corresponding pock…

B subunits of cholera toxin and thermolabile enterotoxin of Escherichia coli have similar adjuvant effect as whole molecules on rotavirus 2/6-VLP spe…

2015

The purpose of this study was to evaluate the adjuvant effect of the B subunits of cholera toxin (CT) and the thermolabile enterotoxin of Escherichia coli (LT) by the intrarectal route of immunization and compare them to the whole molecules CT and LT-R192G, a non toxic mutant of LT, using 2/6-VLP as an antigen, in mice. All molecules induced similar antigen specific antibody titers in serum and feces, whereas different T cell profiles were observed. CTB and LTB, conversely to CT and LT-R192G, did not induce detectable production of IL-2 by antigen specific T cells. Moreover, CTB, conversely to LT-R192G, CT and LTB, did not induce antigen specific CD4+CD25+Foxp3- and Foxp3+ T cells, thus sho…

PHOSPHORORGANISCHE VERBINDUNGEN 991VERSUCHE ZUR AUFKLÄRUNG DER O-SELEKTIVITÄT VON VERBINDUNGEN MIT DER P(O)F-GRUPPE

1982

Abstract The mechanism of the reaction of phosphoryl fluoride ( P(O)F) with alcohols in the presence of an amine is fundamentally different from the reaction of phosphoryl chlorides ( P(O)Cl) with primary or secondary amines. The following observations strongly support this proposal: 1. 1H-NMR-, 31P-NMR- and 19F-NMR-spectroscopic investigations show that methyl-phenyl-phosphinicacid-fluoride and n-butylamine form a thermolabile adduct, which yields the methyl-phenyl-phosphinicacid-amide only very slowly. 2. The rate of the reaction of methyl-phenyl-phosphinicacid-fluoride with ethanol is independent of the basicity of the amine but very sensitive to steric factors. Imidazole (which is only …

Effects of adjuvants of the cholera toxin family on CD4 + T cell responses in a murine model of intrarectal immunization with rotavirus-like particles

2011

Mucosal immunization is an important goal of vaccine development to protect against pathogens that use mucosa as portals of entry. However, the use of non-replicating antigens requires the addition of adjuvants.Cholera-like enterotoxins, cholera toxin (CT) from Vibrio cholerae and the heat-labile enterotoxin (LT) from toxinogenic strains of E. coli, as well as the mutant LR-192G and their B subunits (CTB and LTB) have been shown to increase immune responses against unrelated co-administered antigens by mucosal routes. However, their mechanism of action is very complex and not completely understood and differences exist between holotoxins and B subunits and within molecules, differences exis…

1986

In order to graft methacrylonitrile onto preformed networks containing thermolabile azo groups, the monomer was used to swell the networks and then the temperature raised to the decomposition temperature for the azo groups. The unusually high grafting efficiencies yields (e) achieved are explained in terms of both the differences in the reactivities of the primary radicals formed and side reactions, which lead to additional grafting sites. As an aid to understand the dependence of monomer conversion on that of the initiator a kinetic model is discussed, which involves the consideration of the polymerization taking place both in the homogeneous phase and within the polymer pearls, which can …

Über den Einbau von Endgruppen bei der Polymerisation von Styrol und Vinylacetat mit Acylperoxyden

1954

Bei der peroxydischen Losungspolymerisation von Styrol und Vinylacetat wird der Einbau von brom-markiertem Benzoylperoxyd in Abhangigkeit von der Polymerisationstemperatur untersucht. Bei 50°C und darunter werden ausschlieslich verseifbare, brommarkierte Estergruppen gefunden. Bei 100°C beobachtet man auserdem nichtverseifbare Bromphenyl-Endgruppen. Beim Polyacrylnitril sind die eingebauten Endgruppen thermisch sehr labil und werden beim Erwarmen leicht abgespalten. Insertion of bromine-marked benzoylperoxide in dependence of the temperature of polymerisation in the peroxidic solvent-polymerisation of styrene and vinyl-acetate has been investigated. Exclusively hydrolysable bromine-marked e…