scholarly journals Distribution of chitin in the yeast cell wall. An ultrastructural and chemical study.

1980 ◽  
Vol 85 (2) ◽  
pp. 199-212 ◽  
Author(s):  
J Molano ◽  
B Bowers ◽  
E Cabib
Keyword(s):  
Cell Wall ◽  
Fluorescence Microscopy ◽  
Lectin Binding ◽  
Strong Association ◽  
Fluorescein Isothiocyanate ◽  
Chemical Study ◽  
Total Radioactivity ◽  
Lytic Enzymes ◽  
Derivatives Of ◽  
Lateral Walls

The distribution of chitin in Saccharomyces cervisiae primary septa and cell walls was studied with three methods: electron microscopy of colloidal gold particles coated either with wheat germ agglutinin or with one of two different chitinases, fluorescence microscopy with fluorescein isothiocyanate derivatives of the same markers, and enzymatic treatments of [14C]glucosamine-labeled cells. The septa were uniformly and heavily labeled with the gold-attached markers, an indication that chitin was evenly distributed throughout. To study the localization of chitin in lateral walls, alkali-extracted cell ghosts were used. Observations by electron and fluorescence microscopy suggest that lectin-binding material is uniformly distributed over the whole cell ghost wall. This material also appears to be chitin, on the basis of the analysis of the products obtained after treatment of 14C-labeled cell ghosts with lytic enzymes. The chitin of lateral walls can be specifically removed by treatment with beta-(1 leads to 6)-glucanase containing a slight amount of chitinase. During this incubation approximately 7% of the total radioactivity is solubilized, about the same amount liberated when lateral walls of cell ghosts are completely digested with snail glucanase yield primary septa. It is concluded that the remaining chitin, i.e., greater than 90% of the total, is in the septa. The facilitation of chitin removal from the cell wall by beta-(1 leads to 6)-glucanase indicates a strong association between chitin and beta-(1 leads to 6)-glucan. Covalent linkages between the two polysaccharides were not detected but cannot be excluded.

Involvement of cell surface sugars in recognition, attachment, and appressorium formation by a mycoparasite

1990 ◽  
Vol 36 (11) ◽  
pp. 771-778 ◽  
Author(s):  
M. S. Manocha ◽  
Y. Chen ◽  
N. Rao
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Host Cell ◽  
Germ Tube ◽  
Lectin Binding ◽  
Fluorescein Isothiocyanate ◽  
Appressorium Formation ◽  
Obvious Effect ◽  
Surface Attachment ◽  
Host Cell Surface

Fluorescein isothiocyanate labeled lectin binding techniques have revealed differences in the distribution pattern of glycosyl residues at the cell wall level between fungi that are hosts and those that are nonhosts of the mycoparasite Piptocephalis virginiana, and at the protoplast level between compatible and incompatible hosts. The cell wall of the compatible hosts (Choanephora cucurbitarum and Mortierella pusilla) and an incompatible host (Phascolomyces articulosus), as well as that of the mycoparasite itself, contains glucose and N-acetylglucosamine. However, the cell wall of a nonhost (Mortierella candelabrum) tested positive with lectins specific for various sugars, including not only glucose and N-acetylglucosamine, but also fucose, N-acetylgalactosamine, and galactose. These latter sugars could also be exposed at the surfaces of hosts and of the mycoparasite, but only after mild treatment with proteinase or when grown in a liquid culture. Pretreatment of the mycoparasite with glucose and N-acetylglucosamine inhibited its attachment to the host cell surface, but had no obvious effect on appressorium formation. On the other hand, appressorium formation was inhibited by heat treatment of host cell wall fragments which still permitted attachment, thus indicating that the factors responsible for attachment and for appressorium formation are different. The protoplast surfaces of compatible hosts contained all the sugars listed above and these protoplasts could attach to the germ tube of the mycoparasite. Only lectins specific for N-acetylglucosamine and for glucose were bound at the protoplast surface of the incompatible host; these protoplasts did not attach to the mycoparasite germ tube. Key words: mycoparasite, appressorium formation, lectins, host cell surface, attachment, protoplast surface.

A Computational Method for the Identification of Endolysins and Autolysins

2020 ◽  
Vol 27 (4) ◽  
pp. 329-336 ◽  
Author(s):  
Lei Xu ◽  
Guangmin Liang ◽  
Baowen Chen ◽  
Xu Tan ◽  
Huaikun Xiang ◽  
...  
Keyword(s):  
Support Vector Machine ◽  
Cell Wall ◽  
Experimental Results ◽  
Computational Method ◽  
Lytic Enzyme ◽  
Support Vector ◽  
Lytic Enzymes ◽  
Data Set ◽  
Optimal Feature ◽  
Better Than

Background: Cell lytic enzyme is a kind of highly evolved protein, which can destroy the cell structure and kill the bacteria. Compared with antibiotics, cell lytic enzyme will not cause serious problem of drug resistance of pathogenic bacteria. Thus, the study of cell wall lytic enzymes aims at finding an efficient way for curing bacteria infectious. Compared with using antibiotics, the problem of drug resistance becomes more serious. Therefore, it is a good choice for curing bacterial infections by using cell lytic enzymes. Cell lytic enzyme includes endolysin and autolysin and the difference between them is the purpose of the break of cell wall. The identification of the type of cell lytic enzymes is meaningful for the study of cell wall enzymes. Objective: In this article, our motivation is to predict the type of cell lytic enzyme. Cell lytic enzyme is helpful for killing bacteria, so it is meaningful for study the type of cell lytic enzyme. However, it is time consuming to detect the type of cell lytic enzyme by experimental methods. Thus, an efficient computational method for the type of cell lytic enzyme prediction is proposed in our work. Method: We propose a computational method for the prediction of endolysin and autolysin. First, a data set containing 27 endolysins and 41 autolysins is built. Then the protein is represented by tripeptides composition. The features are selected with larger confidence degree. At last, the classifier is trained by the labeled vectors based on support vector machine. The learned classifier is used to predict the type of cell lytic enzyme. Results: Following the proposed method, the experimental results show that the overall accuracy can attain 97.06%, when 44 features are selected. Compared with Ding's method, our method improves the overall accuracy by nearly 4.5% ((97.06-92.9)/92.9%). The performance of our proposed method is stable, when the selected feature number is from 40 to 70. The overall accuracy of tripeptides optimal feature set is 94.12%, and the overall accuracy of Chou's amphiphilic PseAAC method is 76.2%. The experimental results also demonstrate that the overall accuracy is improved by nearly 18% when using the tripeptides optimal feature set. Conclusion: The paper proposed an efficient method for identifying endolysin and autolysin. In this paper, support vector machine is used to predict the type of cell lytic enzyme. The experimental results show that the overall accuracy of the proposed method is 94.12%, which is better than some existing methods. In conclusion, the selected 44 features can improve the overall accuracy for identification of the type of cell lytic enzyme. Support vector machine performs better than other classifiers when using the selected feature set on the benchmark data set.

Searching for the Evolutionary Design of the Pneumococcal Cell Wall Lytic Enzymes

1993 ◽  
pp. 253-259
Author(s):  
Rubens López ◽  
José L. García ◽  
Eduardo Díaz ◽  
Jesús M. Sanz ◽  
José M. Sánchez-Puelles ◽  
...  
Keyword(s):  
Cell Wall ◽  
Evolutionary Design ◽  
Lytic Enzymes ◽  
Cell Wall Lytic Enzymes

Internalisation of fluorescein isothiocyanate and fluorescein isothiocyanatedextran by suspension-cultured plant cells

1990 ◽  
Vol 96 (4) ◽  
pp. 721-730
Author(s):  
LOUISE COLE ◽  
JULLIAN COLEMAN ◽  
DAVID EVANS ◽  
CHRIS HAWES
Keyword(s):  
Fluorescence Microscopy ◽  
Incubation Period ◽  
Degradation Products ◽  
Plant Cells ◽  
Fluorescein Isothiocyanate ◽  
Kinetic Studies ◽  
Apparent Difference ◽  
Carrot Cells ◽  
Intracellular Compartments ◽  
Vacuolar System

The uptake of pure non-conjugated fluorescein isothiocyanate (FITC) and of the membraneimpermeant probe FITC—dextran into suspensioncultured carrot cells and protoplasts has been investigated. Commercial samples of a 70K (K=103Mr) FITC—dextran were shown to contain contaminant FITC and/or its degradation products, which were rapidly internalised into the vacuolar system of both cells and protoplasts. However, purified samples of the 70K FITC—dextran were taken up into the vacuoles of cells but not protoplasts after a lh incubation period. This apparent difference in the ability of cells and protoplasts to internalise FITC—dextrans was confirmed using samples of both commercial and purified 20K FITC—dextran as putative endocytotic probes. Both confocal and conventional fluorescence microscopy of FITC—treated cells have shown that FITC was internalised into similar intracellular compartments as was observed in cells treated with three-times purified 70K FITC—dextran. Thus, FITC was a useful fluorophore for rapidly labelling both the putative endocytotic compartments and the pleiomorphic vacuolar system of carrot cells. Kinetic studies indicated that FITC entered the cell by diffusion in the form of the neutral molecule. We have shown that treatment of cells or protoplasts with the drug Probenecid reversibly inhibited the uptake of FITC from the cytoplasm into the vacuole. In addition, the uptake of FITC into isolated vacuoles was enhanced in the presence of Mg-ATP

scholarly journals Induction of Fusarium lytic Enzymes by Extracts from Resistant and Susceptible Cultivars of Pea (Pisum sativum L.)

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 976
Author(s):  
Lakshmipriya Perincherry ◽  
Chaima Ajmi ◽  
Souheib Oueslati ◽  
Agnieszka Waśkiewicz ◽  
Łukasz Stępień
Keyword(s):  
Cell Wall ◽  
Plant Extracts ◽  
Plant Cell Wall ◽  
Pathogenic Fungi ◽  
Human Beings ◽  
Cell Wall Degrading Enzymes ◽  
Lytic Enzymes ◽  
Mycelium Growth ◽  
Oat Bran

Being pathogenic fungi, Fusarium produce various extracellular cell wall-degrading enzymes (CWDEs) that degrade the polysaccharides in the plant cell wall. They also produce mycotoxins that contaminate grains, thereby posing a serious threat to animals and human beings. Exposure to mycotoxins occurs through ingestion of contaminated grains, inhalation and through skin absorption, thereby causing mycotoxicoses. The toxins weaken the host plant, allowing the pathogen to invade successfully, with the efficiency varying from strain to strain and depending on the plant infected. Fusariumoxysporum predominantly produces moniliformin and cyclodepsipeptides, whereas F. proliferatum produces fumonisins. The aim of the study was to understand the role of various substrates and pea plant extracts in inducing the production of CWDEs and mycotoxins. Additionally, to monitor the differences in their levels when susceptible and resistant pea plant extracts were supplemented. The cultures of F. proliferatum and F. oxysporum strains were supplemented with various potential inducers of CWDEs. During the initial days after the addition of substrates, the fungus cocultivated with pea extracts and other carbon substrates showed increased activities of β-glucosidase, xylanase, exo-1,4-glucanase and lipase. The highest inhibition of mycelium growth (57%) was found in the cultures of F. proliferatum strain PEA1 upon the addition of cv. Sokolik extract. The lowest fumonisin content was exhibited by the cultures with the pea extracts and oat bran added, and this can be related to the secondary metabolites and antioxidants present in these substrates.

scholarly journals Derivatives of Ribosome-Inhibiting Antibiotic Chloramphenicol Inhibit the Biosynthesis of Bacterial Cell Wall

2018 ◽  
Vol 4 (7) ◽  
pp. 1121-1129 ◽  
Author(s):  
Sivan Louzoun Zada ◽  
Keith D. Green ◽  
Sanjib K. Shrestha ◽  
Ido M. Herzog ◽  
Sylvie Garneau-Tsodikova ◽  
...  
Keyword(s):  
Cell Wall ◽  
Bacterial Cell ◽  
Bacterial Cell Wall ◽  
Derivatives Of
Sign in / Sign up

Export Citation Format

Share Document