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Enzyme degradable polymers

Peng Zhang, Sharif S Nada, Xinle Tan, Bin Deng, Mitchell A Sullivan, Robert G Gilbert
Glycogen, a complex branched polymer of glucose (average chain length ~10 monomer units), is the blood-sugar reservoir in humans and other animals. Certain aspects of its molecular structure relevant to its biological functions are currently unamenable to experimental exploration. Knowledge of these is needed to develop future models for quantitative data-fitting to obtain mechanistic understanding of the biosynthetic processes that give rise to glycogen structure. Monte Carlo simulations of the biosynthesis of this structure with realistic macromolecular parameters reveal how chain growth and stoppage (the latter assumed to be through both the action of glycogen branching enzyme and other degradative enzymes, and by hindrance) control structural features...
May 8, 2018: International Journal of Biological Macromolecules
Muhammad Moniruzzaman, Masahiro Goto
Ionic liquids (ILs), a potentially attractive "green," recyclable alternative to environmentally harmful volatile organic compounds, have been increasingly exploited as solvents and/or cosolvents and/or reagents in a wide range of applications, including pretreatment of lignocellulosic biomass for further processing. The enzymatic delignification of biomass to degrade lignin, a complex aromatic polymer, has received much attention as an environmentally friendly process for clean separation of biopolymers including cellulose and lignin...
May 10, 2018: Advances in Biochemical Engineering/biotechnology
Rune Nygaard Monrad, Jens Eklöf, Kristian B R M Krogh, Peter Biely
Glucuronoyl esterases (GEs) belonging to the carbohydrate esterase family 15 (CE15) are involved in microbial degradation of lignocellulosic plant materials. GEs are capable of degrading complex polymers of lignin and hemicellulose cleaving ester bonds between glucuronic acid residues in xylan and lignin alcohols. GEs promote separation of lignin, hemicellulose and cellulose which is crucial for efficient utilization of biomass as an energy source and feedstock for further processing into products or chemicals...
May 8, 2018: Critical Reviews in Biotechnology
Donghao Wang, Wenyi Ding, Kaiyue Zhou, Shutong Guo, Qiang Zhang, David M Haddleton
Immobilization of enzyme could offer the biocatalyst with increased stability and important recoverability, which plays a vital role for the enzyme's industrial applications. In this study, we present a new strategy to build an intelligent enzyme carrier by coating titania nanoparticles with thermoresponsive epoxy-functionalized polymers. Zero-valent copper mediated living radical polymerization (Cu(0)-LRP) was utilized herein to copolymerize N-isopropylacrylamide (NIPAM) and glycidyl acrylate (GA), directly from an unprotected dopamine-functionalized initiator, in order to obtain an epoxy-containing polymer with terminal anchor for the "grafting to" or "one-pot" modification of titania nanoparticles...
May 8, 2018: Biomacromolecules
Natalie Heimerl, Elisabeth Hommel, Martin Westermann, Doreen Meichsner, Martin Lohr, Christian Hertweck, Arthur R Grossman, Maria Mittag, Severin Sasso
Polyketide synthases (PKSs) occur in many bacteria, fungi and plants. They are highly versatile enzymes involved in the biosynthesis of a large variety of compounds including antimicrobial agents, polymers associated with bacterial cell walls and plant pigments. While harmful algae are known to produce polyketide toxins, sequences of the genomes of non-toxic algae, including those of many green-algal species, have surprisingly revealed the presence of genes encoding type I PKSs. The genome of the model alga Chlamydomonas reinhardtii (Chlorophyta) contains a single type I PKS gene, designated PKS1 (Cre10...
May 4, 2018: Plant Journal: for Cell and Molecular Biology
Bellamkonda Ramakrishna, PapaRao Vaikuntapu, Mohan Krishna Mallakuntla, Bhoopal Bhuvanachandra, Sivaramakrishna Dokku, Sheetal Uikey, Appa Rao Podile
The recombinant C-terminal domain of chitinase C of Chitinophaga pinensis (CpChiC-GH18C ) exhibits the highest activity at pH 6.0 and 35 °C, with a Km of 76.13 (mg-1  ml), a kcat of 10.16 (s-1 ), and a kcat /Km of 0.133 (mg-1  ml s-1 ) on colloidal chitin. Analysis of degradation of (GlcNAc)3-6 oligomers shows that CpChiC-GH18C releases (GlcNAc)2 as the main product, indicating an exo-type cleavage pattern. CpChiC-GH18C hydrolyzes the chitin polymers yielding GlcNAc, (GlcNAc)2 , and (GlcNAc)3 as end products with no sign of processivity...
May 1, 2018: International Journal of Biological Macromolecules
Jenny Arnling Bååth, Antonio Martínez-Abad, Jennie Berglund, Johan Larsbrink, Francisco Vilaplana, Lisbeth Olsson
Background: Galactoglucomannan (GGM) is the most abundant hemicellulose in softwood, and consists of a backbone of mannose and glucose units, decorated with galactose and acetyl moieties. GGM can be hydrolyzed into fermentable sugars, or used as a polymer in films, gels, and food additives. Endo -β-mannanases, which can be found in the glycoside hydrolase families 5 and 26, specifically cleave the mannan backbone of GGM into shorter oligosaccharides. Information on the activity and specificity of different mannanases on complex and acetylated substrates is still lacking...
2018: Biotechnology for Biofuels
Diana B Evstafyeva, Vladimir A Izumrudov, Vladimir I Muronetz, Pavel I Semenyuk
The use of polyelectrolytes is a prospective approach to form nanocomplexes to transport different compounds including proteins. In many cases, the bound protein should be digested after delivery to the target. In the present work, we studied proteolysis of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in the complexes with polyelectrolytes. We have found polyanions to enhance the proteolytic degradation of GAPDH by proteinase K and thermolysin. This effect seems to be caused by destabilization of the protein structure...
April 30, 2018: Soft Matter
Benwei Zhu, Fang Ni, Limin Ning, Yun Sun, Zhong Yao
Marine polysaccharide-degrading enzymes play an important role in marine algae degradation and carbon cycling, especially the alginate lyases. Although many alginate lyases have been characterized, the enzymes with industrial potential are still rather rare. A gene, encoding a new alginate lyase AlgNJ04, has been cloned from the marine bacterium Vibrio sp. NJ04. The recombinant alginate lyase was characterized followed by purification on Ni-NTA Sepharose. It exhibited an optimum activity (2416 U/mg) at pH 7...
April 23, 2018: International Journal of Biological Macromolecules
Anutthaman Parthasarathy, Penelope J Cross, Renwick C J Dobson, Lily E Adams, Michael A Savka, André O Hudson
Tyrosine, phenylalanine and tryptophan are the three aromatic amino acids (AAA) involved in protein synthesis. These amino acids and their metabolism are linked to the synthesis of a variety of secondary metabolites, a subset of which are involved in numerous anabolic pathways responsible for the synthesis of pigment compounds, plant hormones and biological polymers, to name a few. In addition, these metabolites derived from the AAA pathways mediate the transmission of nervous signals, quench reactive oxygen species in the brain, and are involved in the vast palette of animal coloration among others pathways...
2018: Frontiers in Molecular Biosciences
Katia Maso, Antonella Grigoletto, Gianfranco Pasut
Proteins hold a central role in medicine and biology, also confirmed by the several therapeutic applications based on biologic drugs. Such therapies are of great relevance thanks to high potency and safety of proteins. Nevertheless, many proteins as therapeutics might present issues like fast kidney clearance, rapid enzymatic degradation, or immunogenicity. Such defects implicate frequent administrations or administrations at high doses of the therapeutics, thus yielding or exacerbating potential side effects...
2018: Advances in Protein Chemistry and Structural Biology
Kwang-Sook Park, Byoung-Ju Kim, Eugene Lih, Wooram Park, Soo-Hong Lee, Yoon Ki Joung, Dong Keun Han
Artificial scaffolds made up of various synthetic biodegradable polymers have been reported to have many advantages including cheap manufacturing, easy scale up, high mechanical strength, convenient manipulation, and molding into an unlimited variety of shapes. However, the synthetic biodegradable polymers still have the insufficiency for cartilage regeneration owing to their acidic degradation products. To reduce acidification by degradation of synthetic polymers, we incorporated magnesium hydroxide (MH) nanoparticles into porous polymer scaffold not only to effectively neutralize the acidic hydrolysate but also to minimize the structural disturbance of scaffolds...
April 16, 2018: Acta Biomaterialia
Harry P Austin, Mark D Allen, Bryon S Donohoe, Nicholas A Rorrer, Fiona L Kearns, Rodrigo L Silveira, Benjamin C Pollard, Graham Dominick, Ramona Duman, Kamel El Omari, Vitaliy Mykhaylyk, Armin Wagner, William E Michener, Antonella Amore, Munir S Skaf, Michael F Crowley, Alan W Thorne, Christopher W Johnson, H Lee Woodcock, John E McGeehan, Gregg T Beckham
Poly(ethylene terephthalate) (PET) is one of the most abundantly produced synthetic polymers and is accumulating in the environment at a staggering rate as discarded packaging and textiles. The properties that make PET so useful also endow it with an alarming resistance to biodegradation, likely lasting centuries in the environment. Our collective reliance on PET and other plastics means that this buildup will continue unless solutions are found. Recently, a newly discovered bacterium, Ideonella sakaiensis 201-F6, was shown to exhibit the rare ability to grow on PET as a major carbon and energy source...
April 17, 2018: Proceedings of the National Academy of Sciences of the United States of America
Nameer R Baker, Banafshe Khalili, Jennifer B H Martiny, Steven D Allison
Microbial decomposers mediate the return of CO2 to the atmosphere by producing extracellular enzymes to degrade complex plant polymers, making plant carbon available for metabolism. Determining if and how these decomposer communities are constrained in their ability to degrade plant litter is necessary for predicting how carbon cycling will be affected by future climate change. We analyzed mass loss, litter chemistry, microbial biomass, extracellular enzyme activities, and enzyme temperature sensitivities in grassland litter transplanted along a Mediterranean climate gradient in southern California...
April 17, 2018: Ecology
Guiyuan Huang, Qiaozhen Wang, Mingqian Lu, Chao Xu, Fei Li, Rongcan Zhang, Wei Liao, Shushi Huang
Alginate lyases are a group of enzymes that catalyze the depolymerization of alginates into oligosaccharides or monosaccharides. These enzymes have been widely used for a variety of purposes, such as producing bioactive oligosaccharides, controlling the rheological properties of polysaccharides, and performing structural analyses of polysaccharides. The algM4 gene of the marine bacterium Vibrio weizhoudaoensis M0101 encodes an alginate lyase that belongs to the polysaccharide lyase family 7 (PL7). In this study, the kinetic constants V max (maximum reaction rate) and K m (Michaelis constant) of AlgM4 activity were determined as 2...
April 6, 2018: Marine Drugs
Zhifeng Liu, Yujie Liu, Guangming Zeng, Binbin Shao, Ming Chen, Zhigang Li, Yilin Jiang, Yang Liu, Yu Zhang, Hua Zhong
The molecular docking has been employed successfully to study the mechanism of biodegradation in the environmental remediation in the past few years, although medical science and biology are the main application areas for it. Molecular docking is a very convenient and low cost method to understand the reaction mechanism of proteins or enzymes with ligands with a high accuracy. This paper mainly provides a review for the application of molecular docking between organic pollutants and enzymes. It summarizes the fundamental knowledge of molecular docking, such as its theory, available softwares and main databases...
March 27, 2018: Chemosphere
R Andler, A-L Altenhoff, F Mäsing, A Steinbüchel
Cleavage of the backbone of poly(cis-1,4-isoprene) (IR) in solid rubber material was accomplished by the addition of partially purified latex clearing protein (Lcp1VH2 ) using a 200-ml enzyme reactor. Two strategies for the addition of Lcp1VH2 were studied revealing that the daily addition of 50 µg ml-1 of Lcp1VH2 for five days was clearly a more efficient regime in comparison to a one-time addition of 250 µg of Lcp1VH2 at the beginning. Soluble oligo(cis-1,4-isoprene) molecules occurred as degradation products and were identified by ESI-MS and GPC...
March 31, 2018: Biotechnology Progress
Tobias Fecker, Pablo Galaz-Davison, Felipe Engelberger, Yoshie Narui, Marcos Sotomayor, Loreto P Parra, César A Ramírez-Sarmiento
Polyethylene terephthalate (PET) is one of the most-consumed synthetic polymers, with an annual production of 50 million tons. Unfortunately, PET accumulates as waste and is highly resistant to biodegradation. Recently, fungal and bacterial thermophilic hydrolases were found to catalyze PET hydrolysis with optimal activities at high temperatures. Strikingly, an enzyme from Ideonella sakaiensis, termed PETase, was described to efficiently degrade PET at room temperature, but the molecular basis of its activity is not currently understood...
March 27, 2018: Biophysical Journal
Eduardo C Moraes, Thabata M Alvarez, Gabriela F Persinoti, Geizecler Tomazetto, Livia B Brenelli, Douglas A A Paixão, Gabriela C Ematsu, Juliana A Aricetti, Camila Caldana, Neil Dixon, Timothy D H Bugg, Fabio M Squina
Background: Lignin is a heterogeneous polymer representing a renewable source of aromatic and phenolic bio-derived products for the chemical industry. However, the inherent structural complexity and recalcitrance of lignin makes its conversion into valuable chemicals a challenge. Natural microbial communities produce biocatalysts derived from a large number of microorganisms, including those considered unculturable, which operate synergistically to perform a variety of bioconversion processes...
2018: Biotechnology for Biofuels
Aaron C Petrey, Carol A de la Motte
Hyaluronan, a major extracellular matrix component, is an active participant in many disease states, including inflammatory bowel disease (IBD). The synthesis of this dynamic polymer is increased at sites of inflammation. Hyaluronan together with the enzymes responsible for its synthesis, degradation, and its binding proteins, directly modulates the promotion and resolution of disease by controlling recruitment of immune cells, by release of inflammatory cytokines, and by balancing hemostasis. This review discusses the functional significance of hyaluronan in the cells and tissues involved in inflammatory bowel disease pathobiology...
March 21, 2018: Matrix Biology: Journal of the International Society for Matrix Biology
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