Search results for " gel"
showing 10 items of 1051 documents
Assessment of temperature effects on beta-aggregation of native and glycated albumin by FTIR spectroscopy and PAGE: relations between structural chan…
2007
Abstract Structural modifications of bovine serum albumin (BSA) induced by heating, and the involvement of glycation of albumin in such processing were studied by using Fourier transform infrared spectroscopy (FTIR) and polyacrylamide gel electrophoresis (PAGE). For native BSA, heating treatments gave rise to β structures which were amplified to the detriment of α-helix form, and which were associated with increased aggregation. A very high correlation was obtained between FTIR Amide I band evolution and aggregation rate parameters, showing the contribution of β-form in aggregates formation. We further assessed the effect of glycation on protein sensibility to heating treatments. A reductio…
The yeast osmosensitive mutant fps1Δ transformed by the cauliflower BobTIP1;1 aquaporin withstand a hypo-osmotic shock
2005
AbstractOsmoregulation plays an important role in cellular responses to osmotic stress in plants and in yeast. Aquaporins contribute to osmotic adjustment by facilitating transport of water or solutes across membranes. The tonoplastic water channel BobTIP1;1 (original name BobTIP26-1) genes are upregulated during dessication stress in cauliflower meristematic tissue. To investigate the physiological importance of BobTIP1;1, we expressed it in a Saccharomyces cerevisiae osmosensitive mutant fps1Δ. We showed that the defect in the yeast glycerol plasma membrane transporter is complemented by a plant cDNA encoding the aquaporin BobTIP1;1 which is localized in the vacuolar membrane of the compl…
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…
Differential expression and glycosylation of proteins in the rat ileal epithelium in response to Echinostoma caproni infection.
2013
Echinostoma caproni (Trematoda: Echinostomatidae) is an intestinal trematode that has been used as experimental model to investigate the factors determining the expulsion of intestinal helminths. We analyze the changes in the protein expression and glycosylation induced by E. caproni in Wistar rat, a host of low compatibility in which the parasites are rapidly rejected. To determine the changes in protein expression, two-dimensional difference gel electrophoresis was employed using protein extracts from the intestine of naïve and infected rats. The patterns of glycosylation were analyzed by lectin blotting. Those spots showing differential expression or glycosylation were analyzed by mass s…
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…
DEEP EUTECTIC SOLVENTS E LIQUIDI IONICI: SOLVENTI PER LO SVILUPPO DI PROCESSI ECO-COMPATIBILI
2020
L’obiettivo di questi tre anni di Dottorato è stato lo studio e l’utilizzo nuovi solventi di reazione in grado di sostituire i solventi organici classici. In particolare sono stati studiati i Deep Eutectic Solvent (DES) e le miscele di Liquidi Ionici (IL). I DES sono stati utilizzati come solventi per lo studio di reazioni organiche, usate per la formazione di nuovi legami C-C. Nello specifico sono state studiate la reazione di Diels-Alder, e diverse reazioni di coupling C-C catalizzate da Pd. In seguito, i DES sono stati utilizzati per la formazione di nuovi gel supramolecolari, chiamati eutectogel. Questi gel sono stati formati usando come gelator amminoacidi naturali, consentendo quindi …
Palladium Supported on Cross-Linked Imidazolium Network on Silica as Highly Sustainable Catalysts for the Suzuki Reaction under Flow Conditions
2013
Highly cross-linked imidazolium-based materials, obtained by radical oligomerization of bis-vinylimidazolium salts in the presence of 3-mercaptopropyl-modified silica gel, were used as supports for palladium catalysts. Thanks to the high imidazolium loading these materials were able to support a high amount of the metal (10 wt%). Such materials were characterized by several techniques (13C magic angle spinning nuclear magnetic resonance, the Brunauer-Emmett-Teller technique, X-ray photoelectron spectroscopy, and transmission electron microscopy). The palladium catalysts displayed good activity allowing the synthesis of several biphenyl compounds in high yields working with only 0.1 mol% of …
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…