Search results for "Imide"
showing 10 items of 298 documents
Feedback Regulation of Syk by Protein Kinase C in Human Platelets
2019
The spleen tyrosine kinase (Syk) is essential for immunoreceptor tyrosine-based activation motif (ITAM)-dependent platelet activation, and it is stimulated by Src-family kinase (SFK)-/Syk-mediated phosphorylation of Y352 (interdomain-B) and Y525/526 (kinase domain). Additional sites for Syk phosphorylation and protein interactions are known but remain elusive. Since Syk S297 phosphorylation (interdomain-B) was detected in platelets, we hypothesized that this phosphorylation site regulates Syk activity via protein kinase C (PKC)-and cyclic adenosine monophosphate (cAMP)-dependent pathways. ADP, the GPVI-agonist convulxin, and the GPIb&alpha
Chemoselective Dual Labeling of Native and Recombinant Proteins
2017
The attachment of two different functionalities in a site-selective fashion represents a great challenge in protein chemistry. We report site specific dual functionalizations of peptides and proteins capitalizing on reactivity differences of cysteines in their free (thiol) and protected, oxidized (disulfide) forms. The dual functionalization of interleukin 2 and EYFP proceeded with no loss of bioactivity in a stepwise fashion applying maleimide and disulfide rebridging allyl-sulfone groups. In order to ensure broader applicability of the functionalization strategy, a novel, short peptide sequence that introduces a disulfide bridge was designed and site-selective dual labeling in the presenc…
In vivo effect of N-ethylmaleimide (NEM) on the measurement of nitrate in plasma
2016
Bioavailability of nitric oxide in the body may be estimated by measuring the concentration of nitrate in plasma. However, it has not been reported whether sequestering of aminothiols in plasma affects the concentration of nitrate in the samples.N-ethylmaleimide (NEM) sequesters aminothiols in plasma therefore we tested the in vivo effect of NEM on the concentration nitrate in plasma.Blood samples were collected from 56 healthy subjects in EDTA vials, EDTA vials containing PBS (pH7.4) and EDTA vials containing NEM dissolved in PBS. Nonparametric statistical tests were used to study the effect of NEM on the concentration of nitrate in plasma measured by the Griess reagent assay and by an HPL…
Fishing for G-quadruplexes in solution with a perylene diimide derivative labeled with biotins
2018
A new fluorescent, non‐cytotoxic perylene diimide derivative with two biotins at the peri position, PDI2B, has been synthesized. This molecule is able to interact selectively with G‐quadruplexes with scarce or no affinity towards single‐ or double‐stranded DNA. These features have made it possible to design a simple, effective, safe, cheap, and selective method for fishing G‐quadruplex structures in solution by use of PDI2B and streptavidin coated magnetic beads. The new cyclic method reported leads to the recovery of more than 80 % of G‐quadruplex structures from solution, even in the presence of an excess of single‐stranded or duplex DNA as competitors. Moreover, PDI2B is a G4 ligand that…
Characterization of a mutant form of human apolipoprotein B (Thr26_Tyr27del) associated with familial hypobetalipoproteinemia
2016
We have previously identified a deletion mutant of human apoB [apoB (Thr26_Tyr27del)] in a subject with primary hypobetalipoproteinemia. The present study determined the effect of Thr26_Tyr27del mutation on apoB secretion using transfected McA-RH7777 cells. Transient or stable transfection of apoB-48 containing the Thr26_Tyr27del mutation showed drastically reduced secretion of the mutant as compared to wild-type apoB-48. No lipoproteins containing the mutant apoB-48 were secreted into the medium. Incubation of transfected cells in a lipid-rich medium in the presence of cycloheximide showed rapid turnover of cell-associated mutant apoB-48 as compared to that of wild-type apoB-48. Immunofluo…
A method to discriminate between the Candida stellata and Saccharomyces cerevisiae in mixed fermentation on WLD and lysine agar media
2016
This paper presents a simple method to distinguish between Candida stellata and Saccharomyces cerevisiae yeasts during microbiological analyses. The method is based on differential yeast growth on a medium containing cycloheximide and a medium containing lysine as only nitrogen source (lysine agar). The cycloheximide resistance of 45 yeast strains belonging to Candida stellata, Hanseniaspora uvarum, Hanseniaspora guilliermondii, Metschnikowia pulcherrima, Torulaspora delbrueckii, Zygosaccharomyces bailii, Kluyveromyces thermotolerans and Zygoascus hellenicus, and 14 strains of Saccharomyces cerevisiae and Saccharomyces bayanus on WL nutrient agar, was assayed. Cycloheximide resistance is ch…
2019
Epileptic activity without visible convulsions is common in Alzheimer's disease (AD) and may contribute adversely to the disease progress and symptoms. Transgenic mice with amyloid plaque pathology also display epileptic seizures, but those are too infrequent to assess the effect of anti-epileptic treatments. Besides spontaneous seizures, these mice also display frequent epileptic spiking in epidural EEG recordings, and these have provided a means to test potential drug treatment to AD-related epilepsy. However, the origin of EEG spikes in transgenic AD model mice has remained elusive, which makes it difficult to relate electrophysiology with underlying pathology at the cellular and molecul…
Short X···N Halogen Bonds With Hexamethylenetetraamine as the Acceptor
2021
Hexamethylenetetramine (HMTA) and N-haloimides form two types of short (imide)X···N and X–X···N (X = Br, I) halogen bonds. Nucleophilic substitution or ligand-exchange reaction on the peripheral X of X–X···N with the chloride of N-chlorosuccinimide lead to Cl–X···N halogen-bonded complexes. The 1:1 complexation of HMTA and ICl manifests the shortest I···N halogen bond [2.272(5) Å] yet reported for an HMTA acceptor. Two halogen-bonded organic frameworks are prepared using 1:4 molar ratio of HMTA and N-bromosuccinimide, each with a distinct channel shape, one possessing oval and the other square grid. The variations in channel shapes are due to tridentate and tetradentate (imide)Br···N coordi…
Ionic liquid crystals based on viologen dimers: tuning the mesomorphism by varying the conformational freedom of the ionic layer
2016
ABSTRACTWe investigated the liquid crystal behaviour of newly synthesised bistriflimide salts of symmetric viologen dimers. A smectic A phase was observed for intermediate spacer lengths and for relatively long lateral alkyl chains. The systems were characterised by thermal analysis, polarised optical microscopy, X-ray scattering and solid-state NMR. An intermediate ordered smectic phase was also exhibited by the compounds (except for systems with very short lateral chains) consisting of molten layers of alkyl chains and partially ordered ionic layers. These results, relating to the mesomorphic behaviour of viologen salts, are qualitatively compared to those of the more common imidazolium s…