THE CELL WALL POLYSACCHARIDES OF CANDIDA ALBICANS: GLUCAN, MANNAN, AND CHITIN

1960 ◽  
Vol 38 (6) ◽  
pp. 869-881 ◽  
Author(s):  
C. T. Bishop ◽  
F. Blank ◽  
P. E. Gardner
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Copper Complexes ◽  
Moving Boundary ◽  
Periodate Oxidation ◽  
Borate Buffer ◽  
Cell Wall Polysaccharides ◽  
Pathogenic Yeast ◽  
Hydrolysis Of

Cells of Candida albicans, a pathogenic yeast, have been shown to contain, in addition to chitin, a glucan ([α]D − 30°) and a mannan ([α]D + 78°) in the approximate ratio of 1.00:0.64. The two polysaccharides were easily distinguishable by moving boundary electrophoresis in borate buffer and were separated from each other by fractionation of their copper complexes. Methylation and hydrolysis of the glucan yielded the following O-methyl ethers of D-glucose: 2,3,4,6-tetra-O-methyl (7 moles); 2,3,4-tri-O-methyl (13 moles); 2,4,6-tri-O-methyl (trace); 2,4-di-O-methyl (6 moles); and 2-O-methyl (1 mole). It was concluded that the glucan was a highly branched polysaccharide containing β 1 → 6 and β 1 → 3 linked residues. Periodate oxidation of the glucan supported this conclusion.Methylation and hydrolysis of the mannan yielded the following O-methyl ethers of D-mannose: 2,3,4,6-tetra-O-methyl (1.65 moles); 3,4,6-tri-O-methyl (1.00 mole); 2,3,6-tri-O-methyl (0.18 mole); 3,4-di-O-methyl (1.90 moles). The mannan was therefore a highly branched polysaccharide with short chains of α 1 → 2 linked mannose residues joined together by α 1 → 6 linkages. Results of periodate oxidation agreed with this structure.The differences between these two polysaccharides and glucans and mannans found in other yeasts are discussed.

THE WATER-SOLUBLE POLYSACCHARIDES OF DERMATOPHYTES: IV. GALACTOMANNANS I FROM TRICHOPHYTON GRANULOSUM, TRICHOPHYTON INTERDIGITALE, MICROSPORUM QUINCKEANUM, TRICHOPHYTON RUBRUM, AND TRICHOPHYTON SCHÖNLEINII

1965 ◽  
Vol 43 (1) ◽  
pp. 30-39 ◽  
Author(s):  
C. T. Bishop ◽  
M. B. Perry ◽  
F. Blank ◽  
F. P. Cooper
Keyword(s):  
Aqueous Solutions ◽  
Copper Complexes ◽  
Trichophyton Rubrum ◽  
Periodate Oxidation ◽  
Structural Features ◽  
Water Soluble ◽  
Major Constituent ◽  
Branch Points ◽  
Terminal Units ◽  
Hydrolysis Of

A group of polysaccharides, called galactomannans I, were precipitated as their insoluble copper complexes from aqueous solutions of the crude polysaccharides obtained from each of the organisms designated in the title. The five galactomannans I were homogeneous under conditions of electrophoresis and ultracentrifugation and had high positive specific rotations. The major constituent monosaccharide was D-mannose; amounts of D-galactose ranged from nil for the polysaccharide from T. rubrum to 13% for that from T. schönleinii. Methylation and hydrolysis of the five galactomannans I yielded varying amounts of the following: 2,3,5,6-tetra-O-methyl-D-galactose (not present in the products from T. rubrum), 2,3,4,6-tetra-O-methyl-D-mannose, 2,3,4-tri-O-methyl-D-mannose, 2,4,6-tri-O-methyl-D-mannose, 3,4-di-O-methyl-D-mannose, and 3,5-di-O-methyl-D-mannose. Periodate oxidation results agreed with the methylation studies. The gross structural features of each galactomannan I appear to be the same, namely, a basic chain of 1 → 6 linked α-D-mannopyranose units for approximately every 22 of which there is a 1 → 3 linked α-D-mannopyranose residue. Branch points occur along the 1 → 6 linked chain at the C2 positions of the D-mannopyranose units and once in every 45 units at the C2 position of a 1 → 6 linked D-mannofuranose residue. The D-galactose in the polysaccharides is present exclusively as non-reducing terminal furanose units; non-reducing terminal units of D-mannopyranose are also present. The variations in the identities and relative amounts of the non-reducing terminal units were the only apparent differences in the gross structural features within this group of polysaccharides.

scholarly journals Optimization of a minimal synergistic enzyme system for hydrolysis of raw cassava pulp

RSC Advances ◽  
2017 ◽  
Vol 7 (76) ◽  
pp. 48444-48453 ◽  
Author(s):  
Benjarat Bunterngsook ◽  
Thanaporn Laothanachareon ◽  
Suda Natrchalayuth ◽  
Sirithorn Lertphanich ◽  
Tatsuya Fujii ◽  
...  
Keyword(s):  
Cell Wall ◽  
Enzyme System ◽  
Starch Granules ◽  
Cell Wall Polysaccharides ◽  
Cassava Pulp ◽  
Lignocellulosic Wastes ◽  
Hydrolysis Of

Cassava pulp is an underused agricultural by-product comprising residual starch granules entrapped in cell wall polysaccharides, making it unique from other lignocellulosic wastes in terms of enzymatic processing.

scholarly journals Candida albicans phosphate transport, facilitating nucleotide sugar biosynthesis, contributes to cell wall stability.

2021 ◽  
Vol 3 (12) ◽  
Author(s):  
Maikel Acosta-Zaldivar ◽  
Wanjun Qi ◽  
Ning-Ning Liu ◽  
Joann Diray-Arce ◽  
Louise A. Walker ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Enzymatic Reaction ◽  
Phosphate Starvation ◽  
Reaction Rates ◽  
Outer Cell ◽  
Cell Wall Polysaccharides ◽  
Nucleotide Sugar ◽  
Structural Cell ◽  
Chitin Synthases

The Candida albicans high-affinity phosphate transporter Pho84 is required for normal Target of Rapamycin signaling, oxidative stress resistance and virulence of this fungal pathogen. It also contributes to C. albicans’ tolerance of two antifungal drug classes, polyenes and echinocandins. Echinocandins inhibit biosynthesis of a major cell wall component, beta-1,3-glucan. Cells lacking Pho84 were hypersensitive to other forms of cell wall stress beyond echinocandin exposure, while their cell wall integrity signaling response was weak. Metabolomics experiments showed that levels of phosphoric intermediates, including nucleotides like ATP and nucleotide sugars, were low in pho84 mutant compared to wild type cells recovering from phosphate starvation. Non-phosphoric precursors like nucleobases and nucleosides were elevated. Outer cell wall phosphomannan biosynthesis requires a nucleotide sugar,GDP-mannose. The nucleotide sugar UDP-glucose is the substrate of enzymes that synthesize two major structural cell wall polysaccharides, beta-1,3- and beta-1,6-glucan. Another nucleotide sugar, UDP-N-acetylglucosamine, is the substrate of chitin synthases which produce a stabilizing component of the intercellular septum and of lateral cell walls. Lack of Pho84 activity, and phosphate starvation, potentiated pharmacological or genetic perturbation of these enzymes. Our model is that low substrate concentrations of beta-D-glucan- and chitin synthases diminish enzymatic reaction rates and potentiate pharmacologic inhibitors to decrease the yield of their cell wall-stabilizing products. Phosphate import is not conserved between fungal and human cells, and humans do not synthesize beta-D-glucans or chitin. Hence inhibiting these processes simultaneously could yield potent antifungal effects with low toxicity to humans.

The solubilisation and hydrolysis of spinach cell wall polysaccharides in gastric and pancreatic fluids

1995 ◽  
Vol 68 (3) ◽  
pp. 389-394 ◽  
Author(s):  
Janice G Miller ◽  
Callum J Buchanan ◽  
Martin A Eastwood ◽  
Stephen C Fry
Keyword(s):  
Cell Wall ◽  
Cell Wall Polysaccharides ◽  
Hydrolysis Of

scholarly journals Characterization of two cell-wall polysaccharides from Fusicoccum amygdali

1971 ◽  
Vol 125 (2) ◽  
pp. 473-480 ◽  
Author(s):  
M. A. Obaidah ◽  
K. W. Buck
Keyword(s):  
Cell Wall ◽  
Sodium Hydroxide ◽  
Periodate Oxidation ◽  
Water Soluble ◽  
Methylation Analysis ◽  
Cell Wall Polysaccharides ◽  
Partial Acid Hydrolysis ◽  
Polysaccharide Fraction ◽  
Linear Chains ◽  
Soluble Polysaccharide

1. The nature of two polysaccharides (s020 values 6S and 2S respectively in 1m-sodium hydroxide), comprising a fragment (fraction BB, [α]D +236° in 1m-sodium hydroxide), previously isolated from cell walls of Fusicoccum amygdali, has been investigated. 2. Both the major (2S) and minor (6S) components were affected by incubation with α-amylase. The 6S polysaccharide was also attacked by exo-β-(1→3)-glucanase, which is evidence that it contained both α-(1→4)- and β-(1→3)-glucopyranose linkages. By fractionation of the products of α-amylase-treated fraction BB it was possible to obtain a water-insoluble polysaccharide, fraction P ([α]D +290° in 1m-sodium hydroxide, 67% of fraction BB) and a water-soluble polysaccharide, fraction Q ([α]D +16° in 1m-sodium hydroxide, 11% of fraction BB), both of which sedimented as single boundaries with s020 values (in 1m-sodium hydroxide) of 1.7S and 4.6S respectively. 3. Evidence from periodate oxidation, methylation analysis, i.r. spectroscopy and partial acid hydrolysis showed that fraction P consisted of linear chains of α-(1→3)-glucopyranose units with blocks of one or two α-(1→4)-glucopyranose units interspersed at intervals along the main chain. The 2S polysaccharide, from which fraction P is derived, evidently also contains longer blocks of α-(1→4)-glucopyranose units, that are susceptible to α-amylase action. 4. Fraction Q consisted of glucose (88%) with small amounts of galactose, mannose and rhamnose. Evidence from digestion with exo- and endo-β-(1→3)-glucanases, periodate oxidation and methylation analysis suggests that fraction Q consists of a branched galactomannorhamnan core, to which is attached a β-(1→3)-, β-(1→6)-glucan. In the cell wall, chains of α-(1→4)-linked glucopyranose units are linked to fraction Q to form the 6S component of fraction BB.

scholarly journals Metabolic Reprogramming in the Opportunistic Yeast Candida albicans in Response to Hypoxia

mSphere ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Anaïs Burgain ◽  
Faiza Tebbji ◽  
Inès Khemiri ◽  
Adnane Sellam
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Metabolic Pathways ◽  
Membrane Lipids ◽  
Oxygen Depletion ◽  
Metabolic Reprogramming ◽  
Pathogenic Yeast ◽  
Fungal Virulence ◽  
Content Type ◽  
The Impact

ABSTRACT Hypoxia is the predominant condition that the human opportunistic fungus Candida albicans encounters in the majority of the colonized niches within the host. So far, the impact of such a condition on the overall metabolism of this important human-pathogenic yeast has not been investigated. Here, we have undertaken a time-resolved metabolomics analysis to uncover the metabolic landscape of fungal cells experiencing hypoxia. Our data showed a dynamic reprogramming of many fundamental metabolic pathways, such as glycolysis, the pentose phosphate pathway, and different metabolic routes related to fungal cell wall biogenesis. The C. albicans lipidome was highly affected by oxygen depletion, with an increased level of free fatty acids and biochemical intermediates of membrane lipids, including phospholipids, lysophospholipids, sphingolipids, and mevalonate. The depletion of oxygen-dependent lipids such as ergosterol or phosphatidylcholine with longer and polyunsaturated lateral fatty acid chains was observed only at the later hypoxic time point (180 min). Transcriptomics data supported the main metabolic response to hypoxia when matched to our metabolomic profiles. The hypoxic metabolome reflected different physiological alterations of the cell wall and plasma membrane of C. albicans under an oxygen-limiting environment that were confirmed by different approaches. This study provided a framework for future in vivo investigations to examine relevant hypoxic metabolic trajectories in fungal virulence and fitness within the host. IMPORTANCE A critical aspect of cell fitness is the ability to sense and adapt to variations in oxygen levels in their local environment. Candida albicans is an opportunistic yeast that is the most prevalent human fungal pathogen. While hypoxia is the predominant condition that C. albicans encounters in most of its niches, its impact on fungal metabolism remains unexplored so far. Here, we provided a detailed landscape of the C. albicans metabolome that emphasized the importance of many metabolic routes for the adaptation of this yeast to oxygen depletion. The fungal hypoxic metabolome identified in this work provides a framework for future investigations to assess the contribution of relevant metabolic pathways in the fitness of C. albicans and other human eukaryotic pathogens with similar colonized human niches. As hypoxia is present at most of the fungal infection foci in the host, hypoxic metabolic pathways are thus an attractive target for antifungal therapy.

Effect of Dilute-Acid-Hydrolysis Treatments on the Utilization of Wheat Straw by Rumen Bacteria and Free Enzymes

1992 ◽  
Vol 1992 ◽  
pp. 212-212
Author(s):  
F.B. de Castro ◽  
P.M. Hotten ◽  
E.R. Ørskov
Keyword(s):  
Cell Wall ◽  
Acid Hydrolysis ◽  
Wheat Straw ◽  
Effect Of Temperature ◽  
Rumen Bacteria ◽  
Dilute Acid ◽  
Cell Wall Polysaccharides ◽  
Dilute Acid Hydrolysis ◽  
Physical Treatment ◽  
Hydrolysis Of

Extensive hydrolysis of cell wall polysaccharides by rumen bacteria or free enzymes has been reported when lignocellulosic materials had been treated with steam and pressure (Dekker & Wallis, 1983; Castro & Machado, 1989). This has mainly been explained by complete hydrolysis of hemicellulose, lignin depolymerization and redistribution within the cell wall and increasing accessible pore volume by swelling of the cell walls. Physical treatment based on use of steam and pressure alone (auto-hydrolysis) is always associated with the release of toxic levels of furfural and phenolic monomers. These chemicals are able to inhibit the activity of rumen microorganisms, yeasts and free enzymes. To overcome this effect, dilute-acid-hydrolysis at low temperatures and pressures has been proposed (Grohmann et al., 1985). The aim of this study was to evaluate the effect of temperature, sulphuric acid concentration and reaction time on the utilization of treated wheat straw by dilute-acid-hydrolysis, either by rumen bacteria and free enzymes.

scholarly journals The interaction between Carbohydrates and the Antimicrobial Peptide P-113Tri is Involved in the Killing of Candida albicans

2020 ◽  
Vol 8 (2) ◽  
pp. 299 ◽  
Author(s):  
Guan-Yu Lin ◽  
Chuan-Fa Chang ◽  
Chung-Yu Lan
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Antimicrobial Peptide ◽  
Mammalian Cells ◽  
Peptide Binding ◽  
Antifungal Drugs ◽  
Planktonic Cells ◽  
Cell Wall Polysaccharides ◽  
The Difference ◽  
Competition Assays

The emergence of drug resistance to Candida albicans is problematic in the clinical setting. Therefore, developing new antifungal drugs is in high demand. Our previous work indicated that the antimicrobial peptide P-113Tri exhibited higher antifungal activity against planktonic cells, biofilm cells, and clinical isolates of Candida species compared to its parental peptide P-113. In this study, we further investigated the difference between these two peptides in their mechanisms against C. albicans. Microscopic examination showed that P-113 rapidly gained access to C. albicans cells. However, most of the P-113Tri remained on the cell surface. Moreover, using a range of cell wall-defective mutants and competition assays, the results indicated that phosphomannan and N-linked mannan in the cell wall are important for peptide binding to C. albicans cells. Furthermore, the addition of exogenous phosphosugars reduced the efficacy of the peptide, suggesting that negatively charged phosphosugars also contributed to the peptide binding to the cell wall polysaccharides. Finally, using a glycan array, P-113Tri, but not P-113, can bind to other glycans commonly present on other microbial and mammalian cells. Together, these results suggest that P-113 and P-113Tri have fundamental differences in their interaction with C. albicans and candidacidal activities.

scholarly journals The SAGA and NuA4 component Tra1 regulates Candida albicans drug resistance and pathogenesis

2021 ◽  
Author(s):  
Iqra Razzaq ◽  
Matthew D Berg ◽  
Yuwei Jiang ◽  
Julie Genereaux ◽  
Deeva Uthayakumar ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Multiple Stressors ◽  
Fungal Infections ◽  
Transcriptional Profiling ◽  
Kinase Domain ◽  
Pathogenic Yeast ◽  
First Line Therapy ◽  
Arginine Residues ◽  
Phosphoinositide 3 Kinase

Candida albicans is the most common cause of death from fungal infections. Emergence of resistant strains reducing the efficacy of first line therapy with echinocandins such as caspofungin calls for the identification of alternative therapeutic strategies. Tra1 is an essential component of the SAGA and NuA4 transcriptional co-activator complexes. As a PIKK family member, Tra1 is characterized by a C-terminal phosphoinositide 3-kinase domain. In Saccharomyces cerevisiae, the assembly and function of SAGA and NuA4 is compromised by a version of Tra1 (Tra1Q3) with three arginine residues in the putative ATP-binding cleft changed to glutamine, Whole transcriptome analysis of the S. cerevisiae tra1Q3 strain highlights Tra1’s role in global transcription, stress response and cell wall integrity. As a result, tra1Q3 increases susceptibility to multiple stressors, including caspofungin. Moreover, the same tra1Q3 allele in the pathogenic yeast Candida albicans causes similar phenotypes, suggesting that Tra1 broadly mediates the antifungal response across yeast species. Transcriptional profiling in C. albicans identified 68 genes that were differentially expressed when the tra1Q3 strain was treated with caspofungin, as compared to gene expression changes induced by either tra1Q3 or caspofungin alone. Included in this set were genes involved in cell wall maintenance, adhesion and filamentous growth. Indeed, the tra1Q3 allele reduces filamentation and other pathogenesis traits in C. albicans. We identified EVP1, which encodes a putative plasma membrane protein, amongst the Tra1-regulated genes, Disrupting EVP1 results in reduced filamentation and infection capacity in C. albicans. Thus, Tra1 emerges as a promising therapeutic target for fungal infections.

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