Does cell wall integrity in legumes flours modulate physiochemical quality and in vitro starch hydrolysis of gluten-free bread?

2019 ◽  
Vol 59 ◽  
pp. 110-118 ◽  
Author(s):  
Fatma Boukid ◽  
Elena Vittadini ◽  
Federica Lusuardi ◽  
Tommaso Ganino ◽  
Eleonora Carini ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Wall Integrity ◽  
Starch Hydrolysis ◽  
Gluten Free ◽  
Hydrolysis Of

scholarly journals Differential Regulation of the Cell Wall Integrity Mitogen-Activated Protein Kinase Pathway in Budding Yeast by the Protein Tyrosine Phosphatases Ptp2 and Ptp3

1999 ◽  
Vol 19 (11) ◽  
pp. 7651-7660 ◽  
Author(s):  
Christopher P. Mattison ◽  
Scott S. Spencer ◽  
Kurt A. Kresge ◽  
Ji Lee ◽  
Irene M. Ota
Keyword(s):  
Cell Wall ◽  
Protein Tyrosine Phosphatases ◽  
Negative Regulator ◽  
Cell Wall Integrity ◽  
Dependent Manner ◽  
Tyrosine Phosphatases ◽  
Protein Tyrosine ◽  
Growth Defects ◽  
Mitogen Activated Protein

ABSTRACT Mitogen-activated protein kinases (MAPKs) are inactivated by dual-specificity and protein tyrosine phosphatases (PTPs) in yeasts. InSaccharomyces cerevisiae, two PTPs, Ptp2 and Ptp3, inactivate the MAPKs, Hog1 and Fus3, with different specificities. To further examine the functions and substrate specificities of Ptp2 and Ptp3, we tested whether they could inactivate a third MAPK, Mpk1, in the cell wall integrity pathway. In vivo and in vitro evidence indicates that both PTPs inactivate Mpk1, but Ptp2 is the more effective negative regulator. Multicopy expression of PTP2, but not PTP3, suppressed growth defects due to the MEK kinase mutation, BCK1-20, and the MEK mutation,MKK1-386, that hyperactivate this pathway. In addition, deletion of PTP2, but not PTP3, exacerbated growth defects due to MKK1-386. Other evidence supported a role for Ptp3 in this pathway. Expression of MKK1-386 was lethal in the ptp2Δ ptp3Δ strain but not in either single PTP deletion strain. In addition, the ptp2Δ ptp3Δ strain showed higher levels of heat stress-induced Mpk1-phosphotyrosine than the wild-type strain or strains lacking either PTP. The PTPs also showed differences in vitro. Ptp2 was more efficient than Ptp3 at binding and dephosphorylating Mpk1. Another factor that may contribute to the greater effectiveness of Ptp2 is its subcellular localization. Ptp2 is predominantly nuclear whereas Ptp3 is cytoplasmic, suggesting that active Mpk1 is present in the nucleus. Last, PTP2 but not PTP3 transcript increased in response to heat shock in a Mpk1-dependent manner, suggesting that Ptp2 acts in a negative feedback loop to inactivate Mpk1.

Differences in endosperm cell wall integrity in wheat (Triticum aestivum L.) milling fractions impact on the way starch responds to gelatinization and pasting treatments and its subsequent enzymatic in vitro digestibility

2019 ◽  
Vol 10 (8) ◽  
pp. 4674-4684 ◽  
Author(s):  
Konstantinos Korompokis ◽  
Niels De Brier ◽  
Jan A. Delcour
Keyword(s):  
Triticum Aestivum ◽  
Cell Wall ◽  
Cell Walls ◽  
Triticum Aestivum L ◽  
Cell Wall Integrity ◽  
In Vitro Digestibility ◽  
Endosperm Cell ◽  
Amylolytic Enzymes ◽  
Physical Barriers

Intact wheat endosperm cell walls reduce intracellular starch swelling and retard its in vitro digestion by acting as physical barriers to amylolytic enzymes.

scholarly journals O-Mannosyltransferase 1 in Aspergillus fumigatus (AfPmt1p) Is Crucial for Cell Wall Integrity and Conidium Morphology, Especially at an Elevated Temperature

2007 ◽  
Vol 6 (12) ◽  
pp. 2260-2268 ◽  
Author(s):  
Hui Zhou ◽  
Hongyan Hu ◽  
Lijuan Zhang ◽  
Ruoyu Li ◽  
Haomiao Ouyang ◽  
...  
Keyword(s):  
Cell Wall ◽  
Elevated Temperature ◽  
Aspergillus Fumigatus ◽  
Cell Wall Integrity ◽  
Secretory Proteins ◽  
Experimental Conditions ◽  
Human Fungal Pathogen ◽  
Conidium Formation

ABSTRACT Protein O-mannosyltransferases initiate O mannosylation of secretory proteins, which are of fundamental importance in eukaryotes. In this study, the PMT gene family of the human fungal pathogen Aspergillus fumigatus was identified and characterized. Unlike the case in Saccharomyces cerevisiae, where the PMT family is highly redundant, only one member of each PMT subfamily, namely, Afpmt1, Afpmt2, and Afpmt4, is present in A. fumigatus. Mutants with a deletion of Afpmt1 are viable. In vitro and in vivo activity assays confirmed that the protein encoded by Afpmt1 acts as an O-mannosyltransferase (AfPmt1p). Characterization of the ΔAfpmt1 mutant showed that a lack of AfPmt1p results in sensitivity to elevated temperature and defects in growth and cell wall integrity, thereby affecting cell morphology, conidium formation, and germination. In a mouse model, Afpmt1 was not required for the virulence of A. fumigatus under the experimental conditions used.

Hydrolysis of the cell-wall carbohydrates of grasses by carbohydrases in relation to voluntary intake by sheep

1974 ◽  
Vol 83 (1) ◽  
pp. 105-111 ◽  
Author(s):  
D. I. H. Jones ◽  
R. W. Bailey
Keyword(s):  
Cell Wall ◽  
Growth Stages ◽  
Cellulase Digestion ◽  
Acid Detergent Fibre ◽  
Breeding Programmes ◽  
Cell Wall Carbohydrates ◽  
Voluntary Intake ◽  
The Relationship ◽  
Hydrolysis Of

SUMMARYThe relationship between the voluntary dry-matter intake of grasses and their in vitro digestibility (DOMD), chemical composition and susceptibility to enzymic hydrolysis was examined in two experiments. The grasses were artificially dried and represented a range of species and varieties cut at various growth stages.In both experiments some 70% of the observed variation in intake could be attributed to differences in in vitro digestibility between the grasses and between the growth stages when harvested. Estimations of acid detergent fibre, pepsin solubility and cellulose generally accounted for less than 70% of the variation in intake.The enzyme digestion techniques, on the other hand, accounted for up to 79% of the variation. The content of enzymically unhydrolysable cell wall gave the highest correlation with voluntary intake (r = −0·88 and −0·89, residual standard deviation 5·5 and 6·2, for the two experiments).It is concluded that simplified techniques based on cellulase digestion of plant material may be advantageously applied to breeding programmes with the expectation of identifying material high in digestibility and with good intake characteristics.

scholarly journals Octyl Gallate as an Intervention Catalyst to Augment Antifungal Efficacy of Caspofungin

J ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Jong Kim ◽  
Kathleen Chan ◽  
Luisa Cheng
Keyword(s):  
Cell Wall ◽  
Filamentous Fungi ◽  
Fungal Pathogens ◽  
Intervention Strategy ◽  
Cell Wall Integrity ◽  
Fungal Resistance ◽  
Alternative Intervention ◽  
Invasive Infections ◽  
Application Of Cas

Filamentous fungi such as Aspergillus spp. are opportunistic pathogens, which cause highly invasive infections, especially in immunocompromised individuals. Control of such fungal pathogens is increasingly problematic due to the small number of effective drugs available for treatment. Moreover, the increased incidence of fungal resistance to antifungal agents makes this problem a global human health issue. The cell wall integrity system of fungi is the target of antimycotic drugs echinocandins, such as caspofungin (CAS). However, echinocandins cannot completely inhibit the growth of filamentous fungal pathogens, which results in survival/escape of fungi during treatment. Chemosensitization was developed as an alternative intervention strategy, where co-application of CAS with the intervention catalyst octyl gallate (OG; chemosensitizer) greatly enhanced CAS efficacy, thus achieved ≥99.9% elimination of filamentous fungi in vitro. Based on hypersensitive responses of Aspergillus antioxidant mutants to OG, it is hypothesized that, besides destabilizing cell wall integrity, the redox-active characteristic of OG may further debilitate the fungal antioxidant system.

scholarly journals Characterization of the Bifunctional Glycosyltransferase/Acyltransferase Penicillin-Binding Protein 4 of Listeria monocytogenes

2006 ◽  
Vol 188 (5) ◽  
pp. 1875-1881 ◽  
Author(s):  
Joanna Zawadzka-Skomiał ◽  
Zdzislaw Markiewicz ◽  
Martine Nguyen-Distèche ◽  
Bart Devreese ◽  
Jean-Marie Frère ◽  
...  
Keyword(s):  
Cell Wall ◽  
Listeria Monocytogenes ◽  
Chain Elongation ◽  
Lipid Ii ◽  
Food Borne ◽  
Glycan Chain ◽  
Chain Polymerization ◽  
Hydrolysis Of

ABSTRACT Multimodular penicillin-binding proteins (PBPs) are essential enzymes responsible for bacterial cell wall peptidoglycan (PG) assembly. Their glycosyltransferase activity catalyzes glycan chain elongation from lipid II substrate (undecaprenyl-pyrophosphoryl-N-acetylglucosamine-N-acetylmuramic acid-pentapeptide), and their transpeptidase activity catalyzes cross-linking between peptides carried by two adjacent glycan chains. Listeria monocytogenes is a food-borne pathogen which exerts its virulence through secreted and cell wall PG-associated virulence factors. This bacterium has five PBPs, including two bifunctional glycosyltransferase/transpeptidase class A PBPs, namely, PBP1 and PBP4. We have expressed and purified the latter and have shown that it binds penicillin and catalyzes in vitro glycan chain polymerization with an efficiency of 1,400 M−1 s−1 from Escherichia coli lipid II substrate. PBP4 also catalyzes the aminolysis (d-Ala as acceptor) and hydrolysis of the thiolester donor substrate benzoyl-Gly-thioglycolate, indicating that PBP4 possesses both transpeptidase and carboxypeptidase activities. Disruption of the gene lmo2229 encoding PBP4 in L. monocytogenes EGD did not have any significant effect on growth rate, peptidoglycan composition, cell morphology, or sensitivity to β-lactam antibiotics but did increase the resistance of the mutant to moenomycin.

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