China
Africa
Explore chapters and articles related to this topic
Order Tymovirales
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
Röder et al. (2017b) applied the SpyTag/SpyCatcher methodology, introduced by Zakeri et al. (2012) and described in detail in Chapter 25. Thus, the Trichoderma reesei endoglucanase Cel12A was covalently attached to the PVX nanoparticles. The PVX coat was modified to display the short SpyTag sequence of 14 aa residues, whereas the Cel12A enzyme of 220 aa residues was provided C-terminally with the SpyCatcher sequence of 129 aa over 10 aa of doubled G4S linker. This allowed the rapid and specific irreversible attachment of the SpyCatcher fusion protein with, in this case, a ~70% coupling efficiency. The SpyTag-PVX construct therefore provided a universally applicable platform with great promise for future practice by overcoming problems of size constraints and inappropriate aa compositions that may influence the genetic engineering methods, as well as the chemical coupling methods described later.
Biocatalyzed Synthesis of Antidiabetic Drugs
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Glyconjugates with GlcNAc attached to Asn residues were obtained chemically, and were subsequently employed as starting substrate for the ENGase-catalyzed coupling of polysaccharides, as exemplified in Fig. 11.7, to obtain glycoproteins containing the core N-glycan pentasaccharide [Man3(GlcNAc)2] or a complex biantennary glycan [(NeuAcGalGlcNAcMan)2Man(GlcNAc)2] at each of its six asparagine residues. Like so, both a commercially available N175Q Endo M mutant and a E173H Endo A mutant were used to obtain the glycopeptides depicted in Fig. 11.7, showing in vitro and in vivo activity (blood glucose tolerance test in rats), with improved pharmacokinetics compared to pramlintide. Use of Endoglucanase for synthesizing glycopeptides derived from pramlintide.
The Genetics of the Frankia-Actinorhizal Symbiosis
Published in Peter M. Gresshoff, Molecular Biology of Symbiotic Nitrogen Fixation, 2018
Pascal Simonet, Philippe Normand, Ann M. Hirsch, Antoon D. L. Akkermans
Several Frankia strains grown under a number of culture conditions are able to degrade cellulose or carboxymethylcellulose (CMC) into glucose.121 Hence, Frankia must secrete some type of cellulolytic enzymes which of yet are uncharacterized. Such genes have been cloned from pathogenic organisms, and studies are underway to determine whether there is any sequence similarity between these clones and Frankia DNA. Simonet et al.58a found that Clostridium thermocellum cel genes hybridized with Frankia DNA. The cel-like sequence has not been localized yet, nor has the extent of sequence similarity between the C. thermocellum cel clone and the Frankia cel-like gene been established. Reddy et al.106a have also detected hybridization between a cel clone isolated from Erwinia chrysanthemi122 and HFPCcI3 DNA. Interstingly, a cel clone representing an endoglucanase II, an Erwinia protein which is not secreted into the medium, did not exhibit much hybridization to the Frankia DNA, whereas a clone for endoglucanase I, a protein secreted into the medium, strongly hybridized to the HFPCcI3 DNA sequences.
Cellulolytic bacteria in the large intestine of mammals
Published in Gut Microbes, 2022
Alicia Froidurot, Véronique Julliand
Fibro-slime domains bring the substrate close to the cellulases located either in the outer membranes or coupled to extracellular secretion of endoglucanase.121 This is relevant to the fact that, in the same study, more CAZymes were found in the extracellular medium than in the periplasm or outer membrane. In addition, OMVs containing CAZymes are released from the bacterial cells to target plant cell walls. These OMVs contain fibro-slime proteins, cellulases, and hemicellulases. In addition to degrading cellulose, these vesicles had the capacity to degrade hemicelluloses and pectins, although F. succinogenes consumes only sugars released from cellulose degradation.119 Thus, OMVs would facilitate the access to cellulose in F. succinogenes S85 cells. To date, no search for OMVs in the large intestine strains of Fibrobacter spp. has been performed, but it is possible that some strains also use this system to reach cellulose and degrade it. In the genomes of various strains of F. succinogenes isolated from the large intestine of different mammals (horse, monkey, tapir, elephant, and capybara), proteins containing fibro-slime domains were identified. A smaller number of those proteins was observed in several strains of F. intestinalis isolated from omnivorous mammals.74 The lowest number predicted in a genome was 3 for F. intestinalis, whereas F. succinogenes strains had 8–10 distinct proteins containing a fibro-slime domain.74 The mechanisms of cellulose degradation by F. succinogenes and F. intestinalis would be a worthy focus in future studies, for describing better their role in cellulosic and hemicellulosic catabolism.
Mycobacterial biofilms as players in human infections: a review
Published in Biofouling, 2021
Esmeralda Ivonne Niño-Padilla, Carlos Velazquez, Adriana Garibay-Escobar
In contrast, several cellulases have been described in the genus Mycobacterium. Rv0062 codes the endoglucanase CelA1 in M. tuberculosis (Varrot et al. 2005) and MSMEG_1752 in M. smegmatis (Van Wyk et al. 2017). Whether pathogenic or saprophytic mycobacteria use these cellulases for detachment from mature biofilms and colonize other sites of the environmental niche remains to be determined. Moreover, it would be of great interest to explore how cellulose influences biofilm organization in coordination with other carbohydrates, lipids, and structural proteins.
Washingtonia filifera seed extracts inhibit the islet amyloid polypeptide fibrils formations and α-amylase and α-glucosidase activity
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2021
Sonia Floris, Antonella Fais, Rosaria Medda, Francesca Pintus, Alessandra Piras, Amit Kumar, Piotr Marek Kuś, Gunilla Torstensdotter Westermark, Benedetta Era
Controlling the response of carbohydrate hydrolysing enzymes (α-amylase and α-glycosidase) is an effective strategy in facing and/or managing postprandial hyperglycaemia. α-Amylase is endoglucanase, which hydrolyses the internal α-1,4 glycosidic linkage in starch and α-glucosidase is one of the glucosidases located in the brush border surface membrane of intestinal cells, key enzyme for carbohydrate digestion.