Search results for "Fungal Proteins"
showing 10 items of 225 documents
Modulation of the glycerol and ethanol syntheses in the yeast Saccharomyces kudriavzevii differs from that exhibited by Saccharomyces cerevisiae and …
2010
In the last years there is an increasing demand to produce wines with higher glycerol levels and lower ethanol contents. The production of these compounds by yeasts is influenced by many environmental variables, and could be controlled by the choice of optimized cultivation conditions. The present work studies, in a wine model system, the effects of temperature, pH and sugar concentration on the glycerol and ethanol syntheses by yeasts Saccharomyces cerevisiae T73, the type strain of Saccharomyces kudriavzevii IFO 1802(T), and an interspecific hybrid between both species (W27), which was accomplished by the application of response surface methodology based in a central composite circumscrib…
Evidence for the formation of covalent bonds between macromolecules in the domain of the wall of Candida albicans mycelial cells
1989
An O-glycosylated mannoprotein, after its incorporation into the wall, showed an increase in its molecular weight, due at least to its association with N-glycosidic sugar chain(s). This was shown by rendering the material soluble after partial degradation of the wall structure. At present it is unknown whether this phenomenon is due to an additional transglycosylation process or whether the partial degradation of the wall solubilizes a supramolecular structure formed between the original O-glycosylated protein which becomes linked either directly or indirectly through a protein to the N-sugar chain(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…
Expression ofYWP1,a Gene That Encodes a SpecificYarrowia lipolyticaMycelial Cell Wall Protein, inSaccharomyces cerevisiae
1997
Abstract The YWP1 gene encoding a specific mycelial cell wall protein of Yarrowia lipolytica has been cloned and expressed in Saccharomyces cerevisiae using different episomal plasmids. Because the plasmids pYAE35BB and pYAE35ES carrying the YWP1 gene (including the 5′ noncoding promoter sequences) failed to express it, the YWP1 gene was cloned under the control of GAL/CYC or ACT S. cerevisiae promoters. A main band with an apparent molecular mass of 70 kDa was detected by immunoblotting in the cell wall fraction of transformants. Ywp1 processing and incorporation to the cell wall were similar in both Y. lipolytica and S. cerevisiae but not in its final localization in the cell wall. In Y. …
Evidence for the attachment of Hsp150/Pir2 to the cell wall of Saccharomyces cerevisiae through disulfide bridges.
2001
Here we present evidence that Hsp150/Pir2, a member of the Pir family of cell wall proteins, can be extracted from the purified cell walls of Saccharomyces cerevisiae by treatment with beta-mercaptoethanol, demonstrating that at least part of this protein is attached to the cell wall through disulfide bridges. We also present evidence that Pir4, another member of this family, is partly secreted to the growth medium. Finally we propose a hypothesis to explain the relationship between the differently localized forms of particular members of the Pir family of cell wall proteins.
Lack of correlation between trehalose accumulation, cell viability and intracellular acidification as induced by various stresses in Saccharomyces ce…
1998
A pma1-1 mutant of Saccharomyces cerevisiae with reduced H+-ATPase activity and the isogenic wild-type strain accumulated high levels of trehalose in response to a temperature upshift to 40 éC and after addition of 10% ethanol, but only modest levels in response to a rapid drop in external pH and after addition of decanoic acid. There was, however, no correlation between the absolute levels of trehalose in the stressed cells and their viability. All these treatments induced a significant decrease in intracellular pH, and surprisingly, this decrease was very similar in both strains, indicating that intracellular acidification could not be the triggering mechanism for trehalose accumulation i…
Engineering of sugar transporters for improvement of xylose utilization during high-temperature alcoholic fermentation in Ogataea polymorpha yeast
2020
Abstract Background Xylose transport is one of the bottlenecks in the conversion of lignocellulosic biomass to ethanol. Xylose consumption by the wild-type strains of xylose-utilizing yeasts occurs once glucose is depleted resulting in a long fermentation process and overall slow and incomplete conversion of sugars liberated from lignocellulosic hydrolysates. Therefore, the engineering of endogenous transporters for the facilitation of glucose-xylose co-consumption is an important prerequisite for efficient ethanol production from lignocellulosic hydrolysates. Results In this study, several engineering approaches formerly used for the low-affinity glucose transporters in Saccharomyces cerev…
Study of supramolecular structures released from the cell wall of Candida albicans by ethylenediamine treatment
1996
Candida albicans cell wall components were analyzed by ethylenediamine (EDA) treatment. Based on their different solubility properties, the cell wall components produced three fractions (A, B, and C). Fractions B (EDA-soluble, water-insoluble) and C (EDA-insoluble) contained glucan, chitin, and protein in different proportions. After zymolyase (mainly a beta-glucanase complex) or chitinase treatment of fractions B and C, more polysaccharides and proteins were solubilized by a second EDA treatment, suggesting that the solubility of the polymers in EDA depends on the degree of polymer interactions. Western blot analysis using two monoclonal antibodies (1B12 and 4C12) revealed electrophoretic …