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Enzyme degradable polymers

Joana Roßberg, Falko O Rottke, Burkhard Schulz, Andreas Lendlein
The influence of terminal functionalization of oligo(ε-caprolactone)s (OCL) with phenylboronic acid pinacol ester or phenylboronic acid on the enzymatic degradation behavior at the air-water interface is investigated by the Langmuir monolayer degradation technique. While the unsubstituted OCL immediately degrades after injection of the enzyme lipase from Pseudomonas cepacia, enzyme molecules are incorporated into the films based on end-capped OCL before degradation. This incorporation of enzymes does not inhibit or suppress the film degradation, but retards it significantly...
October 20, 2016: Macromolecular Rapid Communications
Xiaohua Zhang, Sami Caner, Emily Kwan, Chunmin Li, Gary D Brayer, Stephen G Withers
Starch provides the major source of caloric intake in many diets. Cleavage of starch into malto-oligosaccharides in the gut is catalyzed by pancreatic alpha-amylase. These oligosaccharides are then further cleaved by gut wall alpha-glucosidases to release glucose, which is absorbed into the bloodstream. Potential surface binding sites for starch on the pancreatic amylase, distinct from the active site of the amylase, have been identified through X-ray crystallographic analyses. The role of these sites in the degradation of both starch granules and soluble starch was probed by the generation of a series of surface variants modified at each site to disrupt binding...
October 19, 2016: Biochemistry
Katrin Niegelhell, Michael Suessenbacher, Katrin Jammernegg, Thomas Ganner, Daniel Schwendenwein, Helmut Schwab, Franz Stelzer, Harald Plank, Stefan Spirk
The creation of nano- and micropatterned polymer films is a crucial step for innumerous applications in science and technology. However, there are several problems associated with environmental aspects concerning the polymer synthesis itself, crosslinkers to induce the patterns as well as toxic solvents used for the preparation and even more important development of the films (e.g. chlorobenzene). In this paper, we present a facile method to produce micro- and nanopatterned biopolymer thin films using enzymes as so called biodevelopers...
October 13, 2016: Biomacromolecules
Mireia Díaz-Lobo, Alda Lisa Concia, Livia Gómez, Pere Clapés, Ignacio Fita, Joan J Guinovart, Joan C Ferrer
Glycogen synthase (GS) and glycogen phosphorylase (GP) are the key enzymes that control, respectively, the synthesis and degradation of glycogen, a multi-branched glucose polymer that serves as a form of energy storage in bacteria, fungi and animals. An abnormal glycogen metabolism is associated with several human diseases. Thus, GS and GP constitute adequate pharmacological targets to modulate cellular glycogen levels by means of their selective inhibition. The compound 1,4-dideoxy-1,4-imino-d-arabinitol (DAB) is a known potent inhibitor of GP...
September 26, 2016: Organic & Biomolecular Chemistry
Lily Khadempour, Kristin E Burnum-Johnson, Erin S Baker, Carrie D Nicora, Bobbie-Jo M Webb-Robertson, Richard A White, Matthew E Monroe, Eric L Huang, Richard D Smith, Cameron R Currie
Herbivores use symbiotic microbes to help derive energy and nutrients from plant material. Leaf-cutter ants are a paradigmatic example, cultivating their mutualistic fungus Leucoagaricus gongylophorus on plant biomass that workers forage from a diverse collection of plant species. Here, we investigate the metabolic flexibility of the ants' fungal cultivar for utilizing different plant biomass. Using feeding experiments and a novel approach in metaproteomics, we examine the enzymatic response of L. gongylophorus to leaves, flowers, oats, or a mixture of all three...
October 1, 2016: Molecular Ecology
Julia Schückel, Stjepan Krešimir Kračun, William G T Willats
Carbohydrates active enzymes (CAZymes) have multiple roles in vivo and are widely used for industrial processing in the biofuel, textile, detergent, paper and food industries. A deeper understanding of CAZymes is important from both fundamental biology and industrial standpoints. Vast numbers of CAZymes exist in nature (especially in microorganisms) and hundreds of thousands have been cataloged and described in the carbohydrate active enzyme database (CAZy). However, the rate of discovery of putative enzymes has outstripped our ability to biochemically characterize their activities...
2016: Journal of Visualized Experiments: JoVE
Pallinti Purushotham, Sung Hyun Cho, Sara M Díaz-Moreno, Manish Kumar, B Tracy Nixon, Vincent Bulone, Jochen Zimmer
Plant cell walls are a composite material of polysaccharides, proteins, and other noncarbohydrate polymers. In the majority of plant tissues, the most abundant polysaccharide is cellulose, a linear polymer of glucose molecules. As the load-bearing component of the cell wall, individual cellulose chains are frequently bundled into micro and macrofibrils and are wrapped around the cell. Cellulose is synthesized by membrane-integrated and processive glycosyltransferases that polymerize UDP-activated glucose and secrete the nascent polymer through a channel formed by their own transmembrane regions...
October 4, 2016: Proceedings of the National Academy of Sciences of the United States of America
Lital Davidi, Sarah Moraïs, Lior Artzi, Doriv Knop, Yitzhak Hadar, Yonathan Arfi, Edward A Bayer
Efficient breakdown of lignocellulose polymers into simple molecules is a key technological bottleneck limiting the production of plant-derived biofuels and chemicals. In nature, plant biomass degradation is achieved by the action of a wide range of microbial enzymes. In aerobic microorganisms, these enzymes are secreted as discrete elements in contrast to certain anaerobic bacteria, where they are assembled into large multienzyme complexes termed cellulosomes. These complexes allow for very efficient hydrolysis of cellulose and hemicellulose due to the spatial proximity of synergistically acting enzymes and to the limited diffusion of the enzymes and their products...
September 27, 2016: Proceedings of the National Academy of Sciences of the United States of America
Teresa Domínguez-Gil, Mijoon Lee, Iván Acebrón-Avalos, Kiran V Mahasenan, Dusan Hesek, David A Dik, Byungjin Byun, Elena Lastochkin, Jed F Fisher, Shahriar Mobashery, Juan A Hermoso
Bacteria grow and divide without loss of cellular integrity. This accomplishment is notable, as a key component of their cell envelope is a surrounding glycopeptide polymer. In Gram-negative bacteria this polymer-the peptidoglycan-grows by the difference between concurrent synthesis and degradation. The regulation of the enzymatic ensemble for these activities is poorly understood. We report herein the structural basis for the control of one such enzyme, the lytic transglycosylase MltF of Pseudomonas aeruginosa...
October 4, 2016: Structure
Raluca Vulpe, Didier Le Cerf, Virginie Dulong, Marcel Popa, Catalina Peptu, Liliana Verestiuc, Luc Picton
The elaboration of chemically crosslinked hydrogels based on collagen (C), hyaluronanic acid (HA) and sericin (S) with different polymer ratios was investigated by in-situ rheology. This reaction was performed via amide or ester bond reaction activated by carbodiimide, in pure water. Prior to molecule crosslinking, the rheological behaviour of the biopolymers (alone or in mixture) was characterized in a semi-dilute concentration regime. Both flow and dynamic measurements showed that uncrosslinked collagen alone appears to be rather elastic with yield stress properties, whereas uncrosslinked HA alone appears to be rather shear thinning and viscoelastic in agreement with entangled polymer behaviour...
December 1, 2016: Materials Science & Engineering. C, Materials for Biological Applications
Jaana Kuuskeri, Mari Häkkinen, Pia Laine, Olli-Pekka Smolander, Fitsum Tamene, Sini Miettinen, Paula Nousiainen, Marianna Kemell, Petri Auvinen, Taina Lundell
BACKGROUND: The white-rot Agaricomycetes species Phlebia radiata is an efficient wood-decaying fungus degrading all wood components, including cellulose, hemicellulose, and lignin. We cultivated P. radiata in solid state cultures on spruce wood, and extended the experiment to 6 weeks to gain more knowledge on the time-scale dynamics of protein expression upon growth and wood decay. Total proteome and transcriptome of P. radiata were analyzed by peptide LC-MS/MS and RNA sequencing at specific time points to study the enzymatic machinery on the fungus' natural growth substrate...
2016: Biotechnology for Biofuels
Birgit Unterweger, Dieter M Bulach, Judith Scoble, David J Midgley, Paul Greenfield, Dena Lyras, Priscilla Johanesen, Geoffrey J Dumsday
: We report the isolation and characterisation of three new cytochrome P450 monooxygenases: CYP101J2, CYP101J3 and CYP101J4. These P450s were derived from Sphingobium yanoikuyae B2, a strain that was isolated from activated sludge based on its ability to fully mineralise 1,8-cineole. Genome sequencing of this strain in combination with purification of native 1,8-cineole-binding proteins enabled identification of 1,8-cineole-binding P450s. The P450 enzymes were cloned, heterologously expressed (N-terminally-His6-tagged) in Escherichia coli BL21 (DE3), purified and spectroscopically characterised...
September 2, 2016: Applied and Environmental Microbiology
N Hugouvieux-Cotte-Pattat
Dickeya, a genus of the Enterobacteriaceae family, all cause plant diseases. They are aggressive necrotrophs that have both a wide geographic distribution and a wide host range. As a plant pathogen, Dickeya has had to adapt to a vegetarian diet. Plants constitute a large storage of carbohydrates; they contain substantial amounts of soluble sugars and the plant cell wall is composed of long polysaccharides. Metabolic functions used by Dickeya in order to multiply during infection are essential aspects of pathogenesis...
2016: Progress in Molecular Biology and Translational Science
S Reverchon, G Muskhelisvili, W Nasser
The pectinolytic Dickeya spp. are Gram-negative bacteria causing severe disease in a wide range of plant species. Although the Dickeya genus was initially restricted to tropical and subtropical areas, two Dickeya species (D. dianthicola and D. solani) emerged recently in potato cultures in Europe. Soft-rot, the visible symptoms, is caused by plant cell wall degrading enzymes, mainly pectate lyases (Pels) that cleave the pectin polymer. However, an efficient colonization of the host requires many additional elements including early factors (eg, flagella, lipopolysaccharide, and exopolysaccharide) that allow adhesion of the bacteria and intermediate factors involved in adaptation to new growth conditions encountered in the host (eg, oxidative stress, iron starvation, and toxic compounds)...
2016: Progress in Molecular Biology and Translational Science
Takehito Nakazawa, Masami Tsuzuki, Toshikazu Irie, Masahiro Sakamoto, Yoichi Honda
Of all of the natural polymers, lignin, an aromatic heteropolymer in plant secondary cell walls, is the most resistant to biological degradation. White-rot fungi are the only known organisms that can depolymerize or modify wood lignin. Investigating the mechanisms underlying lignin biodegradation by white-rot fungi would contribute to the ecofriendly utilization of woody biomass as renewable resources in the future. Efficient gene disruption, which is generally very challenging in the white-rot fungi, was established in Pleurotus ostreatus (the oyster mushroom)...
September 2016: Fungal Biology
Gonzalo de Gonzalo, Dana I Colpa, Mohamed H M Habib, Marco W Fraaije
Lignin forms a large part of plant biomass. It is a highly heterogeneous polymer of 4-hydroxyphenylpropanoid units and is embedded within polysaccharide polymers forming lignocellulose. Lignin provides strength and rigidity to plants and is rather resilient towards degradation. To improve the (bio)processing of lignocellulosic feedstocks, more effective degradation methods of lignin are in demand. Nature has found ways to fully degrade lignin through the production of dedicated ligninolytic enzyme systems. While such enzymes have been well thoroughly studied for ligninolytic fungi, only in recent years biochemical studies on bacterial enzymes capable of lignin modification have intensified...
October 20, 2016: Journal of Biotechnology
Rana Imani, Wei Shao, Samira Taherkhani, Shahriar Hojjati Emami, Satya Prakash, Shahab Faghihi
The aim of this study is to improve hydrocolloid stability and siRNA transfection ability of a reduced graphene oxide (rGO) based nano-carrier using a phospholipid-based amphiphilic polymer (PL-PEG) and cell penetrating peptide (CPPs). The dual functionalized nano-carrier is comprehensively characterized for its chemical structure, size, surface charge and morphology as well as thermal stability. The nano-carrier cytocompatibility, siRNA condensation ability both in the presence and absence of enzyme, endosomal buffering capacity, cellular uptake and intracellular localization are also assessed...
November 1, 2016: Colloids and Surfaces. B, Biointerfaces
Dávid Juriga, Krisztina Nagy, Angéla Jedlovszky-Hajdú, Katalin Perczel-Kovách, Yong Mei Chen, Gábor Varga, Miklós Zrínyi
Development of novel biodegradable and biocompatible scaffold materials with optimal characteristics is important for both preclinical and clinical applications. The aim of the present study was to analyze the biodegradability of poly(aspartic acid)-based hydrogels, and to test their usability as scaffolds for MG-63 osteoblast-like cells. Poly(aspartic acid) was fabricated from poly(succinimide) and hydrogels were prepared using natural amines as cross-linkers (diaminobutane and cystamine). Disulfide bridges were cleaved to thiol groups and the polymer backbone was further modified with RGD sequence...
September 14, 2016: ACS Applied Materials & Interfaces
Yashira M Zayas-Gonzalez, David M Lynn
We report the fabrication of reactive and degradable cross-linked polymer multilayers by the reactive/covalent layer-by-layer assembly of a non-degradable azlactone-functionalized polymer [poly(2-vinyl-4,4-dimethylazlactone), PVDMA] with hydrolytically or enzymatically degradable polyamine building blocks. Fabrication of multilayers using PVDMA and a hydrolytically degradable poly(β-amino ester) (PBAE) containing primary amine side chains yielded multilayers (∼100 nm thick) that degraded over ∼12 days in physiologically relevant media...
September 12, 2016: Biomacromolecules
Tao Sheng, Lei Zhao, Ling-Fang Gao, Wen-Zong Liu, Min-Hua Cui, Ze-Chong Guo, Xiao-Dan Ma, Shih-Hsin Ho, Ai-Jie Wang
BACKGROUND: Lignocellulosic biomass is one of earth's most abundant resources, and it has great potential for biofuel production because it is renewable and has carbon-neutral characteristics. Lignocellulose is mainly composed of carbohydrate polymers (cellulose and hemicellulose), which contain approximately 75 % fermentable sugars for biofuel fermentation. However, saccharification by cellulases is always the main bottleneck for commercialization. Compared with the enzyme systems of fungi, bacteria have evolved distinct systems to directly degrade lignocellulose...
2016: Biotechnology for Biofuels
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