Search results for "Amide"
showing 10 items of 3119 documents
The shell-forming proteome of Lottia gigantea reveals both deep conservations and lineage-specific novelties
2013
19 pages; International audience; Proteins that are occluded within the molluscan shell, the so-called shell matrix proteins (SMPs), are an assemblage of biomolecules attractive to study for several reasons. They increase the fracture resistance of the shell by several orders of magnitude, determine the polymorph of CaCO(3) deposited, and regulate crystal nucleation, growth initiation and termination. In addition, they are thought to control the shell microstructures. Understanding how these proteins have evolved is also likely to provide deep insight into events that supported the diversification and expansion of metazoan life during the Cambrian radiation 543 million years ago. Here, we p…
Synthesis and evaluation of a glibenclamide glucose-conjugate: a potential new lead compound for substituted glibenclamide derivatives as islet imagi…
2007
The search for novel SUR1-ligands originates from the idea to influence the in vivo behaviour by adding new structural moieties to the glibenclamide structure while preserving its binding affinity. Important application of novel conjugates might be their use as radioactively labelled tracer probes in the non-invasive investigation of the islet mass. It is known that the imaging quality of a tracer could be improved by increasing its hydrophilicity, which leads to a reduced plasma protein binding and diminished the unspecific uptake by various organs. In this study the glucose molecule was chosen as a substitute of glibenclamide to enhance hydrophilicity. As expected glucose conjugation lead…
Identification of Two Mannoproteins Released from Cell Walls of a Saccharomyces cerevisiae mnn1 mnn9 Double Mutant by Reducing Agents
1999
The cell wall of Saccharomyces cerevisiae represents some 30% of the total weight of the cell and is made up of β-glucans, mannose-containing glycoproteins (mannoproteins), and small amounts of chitin (9, 15). The mannoproteins can be divided into three groups according to the linkages that bind them to the structure of the cell wall: (i) noncovalently bound, (ii) covalently bound to the structural glucan, and (iii) disulfide bound to other proteins that are themselves covalently bound to the structural glucan of the cell wall (8). Our work has focused on the disulfide-bound mannoproteins, probably the least well known of the three groups mentioned above. Previous work (25) showed that trea…
Killer toxin of Hanseniaspora uvarum
1990
The yeast Hanseniaspora uvarum liberates a killer toxin lethal to sensitive strains of the species Saccharomyces cerevisiae. Secretion of this killer toxin was inhibited by tunicamycin, an inhibitor of N-glycosylation, although the mature killer protein did not show any detectable carbohydrate structures. Culture supernatants of the killer strain were concentrated by ultrafiltration and the extracellular killer toxin was precipitated with ethanol and purified by ion exchange chromatography. SDS-PAGE of the electrophoretically homogenous killer protein indicated an apparent molecular mass of 18,000. Additional investigations of the primary toxin binding sites within the cell wall of sensitiv…
Cell wall mannoproteins during the population growth phases in Saccharomyces cerevisiae.
1987
Mannoproteins from cell walls of Saccharomyces cerevisiae synthesized at successive stages of the population growth cycle have been solubilized with Zymolyase and subsequently analyzed. The major change along the population cycle concerned a large size mannoprotein material; the size of the newly-synthesized molecules varied from 120,000–500,000 (mean of about 200,000) at early exponential phase to 250,000–350,000 (mean of about 300,000) at late exponential phase. These differences are due to modifications in the amount of N-glycosidically linked mannose residues, since the size of the peptide moiety was 90,000–100,000 at all growth stages and the level of O-glycosylation changed only sligh…
Highly sensitive monoclonal antibody-based immunoassays for the analysis of fluopyram in food samples
2019
Monoclonal antibody-based techniques have become a useful analytical technology in the agro-food sector. Nowadays, residues of the recently registered fungicide fluopyram are increasingly being found in quality control programs. In the present study, novel chemical derivatives of this pesticide were prepared and specific and high-affinity monoclonal antibodies to fluopyram were raised for the first time. Moreover, immunoassays to fluopyram were developed in two alternative enzyme-linked immunosorbent assay formats, using homologous and heterologous assay conjugates, with limits of detection below 0.05 µg L−1. The optimized immunoassays were applied to the analysis of fluopyram in fortified …
Microtubule distribution in gravitropic protonemata of the mossCeratodon
1990
Tip cells of dark-grown protonemata of the moss Ceratodon purpureus are negatively gravitropic (grow upward). They possess a unique longitudinal zonation: (1) a tip group of amylochloroplasts in the apical dome, (2) a plastid-free zone, (3) a zone of significant plastid sedimentation, and (4) a zone of mostly non-sedimenting plastids. Immunofluorescence of vertical cells showed microtubules distributed throughout the cytoplasm in a mostly axial orientation extending through all zones. Optical sectioning revealed a close spatial association between microtubules and plastids. A majority (two thirds) of protonemata gravistimulated for > 20 min had a higher density of microtubules near the lowe…
Sustainable and cost-efficient electro-synthesis of formamidine acetate from cyanamide in aqueous acidic electrolyte
2021
Formamidine represents a versatile building block in synthetic organic chemistry. We developed a new electrochemical synthesis of formamidine acetate by cathodic reduction of cyanamide in an aqueous electrolyte and in high yield. The crude product could be used for further conversions, such as to pyrimidines without purification. Compared to established synthetic routes neither prior processing of cyanamide was necessary, nor precious transition-metal catalyst were required, nor any reagent waste was produced, and only biocompatible and sustainable solvents were employed for this process, following the requirements of green chemistry.
Isolation of carcinoembryonic antigen N-terminal domains (N-A1) from soluble aggregates
2011
Abstract Carcinoembryonic antigen (CEA) was identified as a prominent tumor-associated antigen in human colorectal cancer and it is still intensively investigated. However, its physiological role remains unclear. The CEA molecule is composed of seven highly hydrophobic, immunoglobulin-like domains, six of which contain a single disulphide bridge. The production of recombinant protein containing Ig-like domains in bacterial expression systems often results in partial degradation or insolubility due to aggregation hampering the analysis of their native structure and function. Here, we present a new method of expression and purification of CEA N-terminal domains (N-A1) fused to MBP in Escheric…
German Adjuvant Intergroup Node Positive (GAIN) study: A phase III trial to compare IDD-ETC versus EC-TX in patients with node-positive primary breas…
2014
1009 Background: Intense dose-dense (idd) epirubicin (E), paclitaxel (T), cyclophosphamide (C) (idd-ETC) resulted in a superior disease-free (DFS) and overall survival (OS) compared to conventional...