keyword
MENU ▼
Read by QxMD icon Read
search

Enzyme degradable polymers

keyword
https://www.readbyqxmd.com/read/28329766/complex-pectin-metabolism-by-gut-bacteria-reveals-novel-catalytic-functions
#1
Didier Ndeh, Artur Rogowski, Alan Cartmell, Ana S Luis, Arnaud Baslé, Joseph Gray, Immacolata Venditto, Jonathon Briggs, Xiaoyang Zhang, Aurore Labourel, Nicolas Terrapon, Fanny Buffetto, Sergey Nepogodiev, Yao Xiao, Robert A Field, Yanping Zhu, Malcolm A O'Neill, Breeanna R Urbanowicz, William S York, Gideon J Davies, D Wade Abbott, Marie-Christine Ralet, Eric C Martens, Bernard Henrissat, Harry J Gilbert
The metabolism of carbohydrate polymers drives microbial diversity in the human gut microbiota. It is unclear, however, whether bacterial consortia or single organisms are required to depolymerize highly complex glycans. Here we show that the gut bacterium Bacteroides thetaiotaomicron uses the most structurally complex glycan known: the plant pectic polysaccharide rhamnogalacturonan-II, cleaving all but 1 of its 21 distinct glycosidic linkages. The deconstruction of rhamnogalacturonan-II side chains and backbone are coordinated to overcome steric constraints, and the degradation involves previously undiscovered enzyme families and catalytic activities...
March 22, 2017: Nature
https://www.readbyqxmd.com/read/28324320/tailoring-the-properties-of-mpeg-plla-nanoparticles-for-better-encapsulation-and-tuned-release-of-the-hydrophilic-anticancer-drug
#2
Sachin S Surwase, Neha M Munot, Bhaskar B Idage, Susheela B Idage
Gemcitabine is used as a first-line drug for treating many solid tumours. However, it suffers from a major drawback of strong side effects and short plasma half-life because of degradation by enzyme when administered intravenously. Polyesters and copolyesters are the most widely used and preferred class of biodegradable polymer. In the present work, efforts have been made to prepare poly(ethylene glycol) monomethoxy ether-poly(L-lactide) (mPEG-PLLA), a biodegradable amphiphilic copolymer with a view to improve the entrapment and tuned release of hydrophilic drug gemcitabine...
March 21, 2017: Drug Delivery and Translational Research
https://www.readbyqxmd.com/read/28319778/polyhydroxyalkanoates-pha-production-from-synthetic-waste-using-pseudomonas-pseudoflava-pha-synthase-enzyme-activity-analysis-from-p-pseudoflava-and-p-palleronii
#3
M Venkateswar Reddy, Yasuteru Mawatari, Rui Onodera, Yuki Nakamura, Yuka Yajima, Young-Cheol Chang
Synthetic wastewater (SW) at various carbon concentrations (5-60g/l) were evaluated for polyhydroxyalkanoates (PHA) production using the bacteria Pseudomonas pseudoflava. Bacteria showed highest PHA production with 20g/l (57±5%), and highest carbon removal at 5g/l (74±6%) concentrations respectively. Structure, molecular weight, and thermal properties of the produced PHA were evaluated using various analytical techniques. Bacteria produced homo-polymer [poly-3-hydroxybutyrate (P3HB)] when only acetate was used as carbon source; and it produced co-polymer [poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) P(3HB-co-3HV)] by addition of co-substrate propionate...
March 4, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28314873/exploring-the-bioprospecting-and-biotechnological-potential-of-white-rot-and-anaerobic-neocallimastigomycota-fungi-peptidases-esterases-and-lignocellulolytic-enzymes
#4
REVIEW
Ronivaldo Rodrigues da Silva, Rafael Pedezzi, Tatiane Beltramini Souto
Fungi constitute an invaluable natural resource for scientific research, owing to their diversity; they offer a promising alternative for bioprospecting, thus contributing to biotechnological advances. For a long time, extensive information has been exploited and fungal products have been tested as a source of natural compounds. In this context, enzyme production remains a field of interest, since it offers an efficient alternative to the hazardous processes of chemical transformations. Owing to their vast biodiversity and peculiar biochemical characteristics, two fungal categories, white-rot and anaerobic Neocallimastigomycota, have gathered considerable attention for biotechnological applications...
March 17, 2017: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/28285078/biodegradable-inorganic-organic-hybrids-of-methacrylate-star-polymers-for-bone-regeneration
#5
Justin J Chung, Yuki Fujita, Siwei Li, Molly M Stevens, Toshihiro Kasuga, Theoni K Georgiou, Julian R Jones
Hybrids that are molecular scale co-networks of organic and inorganic components are promising biomaterials, improving the brittleness of bioactive glass and the strength of polymers. Methacrylate polymers have high potential as the organic source for hybrids since they can be produced, through controlled polymerization, with sophisticated polymer architectures that can bond to silicate networks. Previous studies showed the mechanical properties of hybrids can be modified by polymer architecture and molar mass (MM)...
March 8, 2017: Acta Biomaterialia
https://www.readbyqxmd.com/read/28277671/enzyme-cleavable-polymeric-micelles-for-the-intracellular-de-livery-of-pro-apoptotic-peptides
#6
Hanna B Kern, Selvi Srinivasan, Anthony J Convertine, David Hockenbery, Oliver W Press, Patrick S Stayton
Peptides derived from the third Bcl-2 homology domain (BH3) renormalize apoptotic signaling by antagonizing pro-survival Bcl-2 family members. They serve as a model for potential peptide drugs that possess therapeutic activities but are limited by delivery barriers including short circulation half-lives and poor penetration into cells. A diblock polymeric micelle carrier for the BIM BH3 peptide was recently described that demonstrated anti-tumor activity in a B-cell lymphoma xenograft model [Berguig et al., Mol Ther, 2015]...
March 9, 2017: Molecular Pharmaceutics
https://www.readbyqxmd.com/read/28270073/colon-cancer-and-specific-ways-to-deliver-drugs-to-the-large-intestine
#7
Hossein Derakhshankhah, Zhila Izadi, Alireza Lotfabadi, Loghman Alaei, Ali Akbar Saboury, Rassoul Dinarvand, Adeleh Divsalar, Arefeh Seyedarabi, Ebrahim Barzegari, Mina Evini
BACKGROUND: It has been postulated that colon cancer is the third cause of cancer death worldwide. Recently, colon-targeted drug delivery systems have been developed for improving systemic drug delivery and treatment of local colon associated diseases. Using such drug delivery systems increases the drug's effectiveness and results in reduced systemic side effects. Drug delivery systems formulated for the colon requires that the triggering of drug release mechanism is designed based on the colon's physiological conditions...
February 13, 2017: Anti-cancer Agents in Medicinal Chemistry
https://www.readbyqxmd.com/read/28267318/modular-synthetic-approach-for-adjusting-the-disassembly-rates-of-enzyme-responsive-polymeric-micelles
#8
Assaf J Harnoy, Marina Buzhor, Einat Tirosh, Rona Shaharabani, Roy Beck, Roey J Amir
Self-assembled nanostructures and their stimuli-responsive degradation have been recently explored to meet the increasing need for advanced biocompatible and biodegradable materials for various biomedical applications. Incorporation of enzymes as triggers that can stimulate the degradation and disassembly of polymeric assemblies may be highly advantageous owing to their high selectivity and natural abundance in all living organisms. One of the key factors to consider when designing enzyme-responsive polymers is the ability to fine-tune the sensitivity of the platform toward its target enzyme in order to control the disassembly rate...
March 21, 2017: Biomacromolecules
https://www.readbyqxmd.com/read/28252940/design-strategies-of-stimuli-responsive-supramolecular-hydrogels-relying-on-structural-analyses-and-cell-mimicking-approaches
#9
Hajime Shigemitsu, Itaru Hamachi
Stimuli-responsive hydrogels are intriguing biomaterials useful for spatiotemporal controlled release of drugs, cells, and biological cues, cell engineering for various applications, and medical diagnosis. To date, many physical and chemical stimuli-responsive polymer hydrogels have been developed by chemical modification of polymer chains and cross-linking points. In particular, conjugation with biomolecules to polymers produced promising biomolecule-responsive hydrogels. These examples clearly indicate high potentials of stimuli-responsive hydrogels as promising biomaterials...
March 2, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/28251581/chitin-and-its-effects-on-inflammatory-and-immune-responses
#10
REVIEW
Daniel Elieh Ali Komi, Lokesh Sharma, Charles S Dela Cruz
Chitin, a potential allergy-promoting pathogen-associated molecular pattern (PAMP), is a linear polymer composed of N-acetylglucosamine residues which are linked by β-(1,4)-glycosidic bonds. Mammalians are potential hosts for chitin-containing protozoa, fungi, arthropods, and nematodes; however, mammalians themselves do not synthetize chitin and thus it is considered as a potential target for recognition by mammalian immune system. Chitin is sensed primarily in the lungs or gut where it activates a variety of innate (eosinophils, macrophages) and adaptive immune cells (IL-4/IL-13 expressing T helper type-2 lymphocytes)...
March 1, 2017: Clinical Reviews in Allergy & Immunology
https://www.readbyqxmd.com/read/28250957/the-mechanism-behind-the-selection-of-two-different-cleavage-sites-in-nag-nam-polymers
#11
Marko Mihelič, Kristina Vlahoviček-Kahlina, Miha Renko, Stephane Mesnage, Andreja Doberšek, Ajda Taler-Verčič, Andreja Jakas, Dušan Turk
Peptidoglycan is a giant molecule that forms the cell wall that surrounds bacterial cells. It is composed of alternating N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) residues connected by β-(1,4)-glycosidic bonds and cross-linked with short polypeptide chains. Owing to the increasing antibiotic resistance against drugs targeting peptidoglycan synthesis, studies of enzymes involved in the degradation of peptidoglycan, such as N-acetylglucos-aminidases, may expose new, valuable drug targets. The scientific challenge addressed here is how lysozymes, muramidases which are likely to be the most studied enzymes ever, and bacterial N-acetylglucosaminidases discriminate between two glycosidic bonds that are different in sequence yet chemically equivalent in the same NAG-NAM polymers...
March 1, 2017: IUCrJ
https://www.readbyqxmd.com/read/28242654/cellulose-derived-oligomers-act-as-damage-associated-molecular-patterns-and-trigger-defense-like-responses
#12
Clarice de Azevedo Souza, Shundai Li, Andrew Z Lin, Freddy Boutrot, Guido Grossmann, Cyril Zipfel, Shauna Somerville
The plant cell wall, often the site of initial encounters between plants and their microbial pathogens, is composed of a complex mixture of cellulose, hemicellulose and pectin polysaccharides, as well as proteins. The concept of damage-associated molecular patterns (DAMPs) was proposed to describe plant elicitors like oligogalacturonides (OGs), which can be derived by the breakdown of the pectin homogalacturon by pectinases. OGs act via many of the same signaling steps as pathogen- or microbe-associated molecular patterns (PAMPs) to elicit defenses and provide protection against pathogens...
February 27, 2017: Plant Physiology
https://www.readbyqxmd.com/read/28238914/biochemical-and-biophysical-properties-of-a-metagenome-derived-gh5-endoglucanase-displaying-an-unconventional-domain-architecture
#13
Agnes C Pimentel, Gabriela C G Ematsu, Marcelo V Liberato, Douglas A A Paixão, João Paulo L Franco Cairo, Fernanda Mandelli, Robson Tramontina, César A Gandin, Mario de Oliveira Neto, Fabio M Squina, Thabata M Alvarez
Endoglucanases are key enzymes in the degradation of cellulose, the most abundant polymer on Earth. The aim of this work was to perform the biochemical and biophysical characterization of CelE2, a soil metagenome derived endoglucanase. CelE2 harbors a conserved domain from glycoside hydrolase family 5 (GH5) and a C-terminal domain with identity to Calx-beta domains. The recombinant CelE2 displayed preference for hydrolysis of oat beta-glucan, followed by lichenan and carboxymethyl cellulose. Optimum values of enzymatic activity were observed at 45°C and pH 5...
February 24, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28238837/molecular-weight-dependent-degradation-and-drug-release-of-surface-eroding-poly-ethylene-carbonate
#14
Adam Bohr, Yingya Wang, Necati Harmankaya, Jorrit J Water, Stefania Baldursdottír, Kristoffer Almdal, Moritz Beck-Broichsitter
Poly(ethylene carbonate) (PEC) is an unique biomaterial showing significant potential for controlled drug delivery applications. The current study investigated the impact of the molecular weight on the biological performance of drug-loaded PEC films. Following the preparation and thorough physicochemical characterization of diverse PEC (molecular weights: 85, 110, 133, 174 and 196 kDa), the degradation and drug release behavior of rifampicin- and bovine serum albumin-loaded PEC films was investigated in vitro (in the presence and absence of cholesterol esterase), in cell culture (RAW264...
February 23, 2017: European Journal of Pharmaceutics and Biopharmaceutics
https://www.readbyqxmd.com/read/28238658/role-of-lotr1-in-nutrient-transport-through-organization-of-spatial-distribution-of-root-endodermal-barriers
#15
Baohai Li, Takehiro Kamiya, Lothar Kalmbach, Mutsumi Yamagami, Katsushi Yamaguchi, Shuji Shigenobu, Shinichiro Sawa, John M C Danku, David E Salt, Niko Geldner, Toru Fujiwara
The formation of Casparian strips and suberin lamellae at the endodermis limits the free diffusion of nutrients and harmful substances via the apoplastic space between the soil solution and the stele in roots [1-3]. Casparian strips are ring-like lignin polymers deposited in the middle of anticlinal cell walls between endodermal cells and fill the gap between them [4-6]. Suberin lamellae are glycerolipid polymers covering the endodermal cells and likely function as a barrier to limit transmembrane movement of apoplastic solutes into the endodermal cells [7, 8]...
March 6, 2017: Current Biology: CB
https://www.readbyqxmd.com/read/28231510/lipopolyplex-potentiates-anti-tumor-immunity-of-mrna-based-vaccination
#16
Stefano Persano, Maria L Guevara, Zhaoqi Li, Junhua Mai, Mauro Ferrari, Pier Paolo Pompa, Haifa Shen
mRNA-based vaccines have the benefit of triggering robust anti-cancer immunity without the potential danger of genome integration from DNA vaccines or the limitation of antigen selection from peptide vaccines. Yet, a conventional mRNA vaccine comprising of condensed mRNA molecules in a positively charged protein core structure is not effectively internalized by the antigen-presenting cells. It cannot offer sufficient protection for mRNA molecules from degradation by plasma and tissue enzymes either. Here, we have developed a lipopolyplex mRNA vaccine that consists of a poly-(β-amino ester) polymer mRNA core encapsulated into a 1,2-dioleoyl-sn-glycero-3-ethylphosphocholine/1,2-dioleoyl-sn-glycero-3-phosphatidyl-ethanolamine/1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000 (EDOPC/DOPE/DSPE-PEG) lipid shell...
May 2017: Biomaterials
https://www.readbyqxmd.com/read/28231319/development-of-a-keratinase-activity-assay-using-recombinant-chicken-feather-keratin-substrates
#17
Hyeon-Su Jin, Seon Yeong Park, Kyungmin Kim, Yong-Jik Lee, Gae-Won Nam, Nam Joo Kang, Dong-Woo Lee
Poultry feathers consist mainly of the protein keratin, which is rich in β-pleated sheets and consequently resistant to proteolysis. Although many keratinases have been identified, the reasons for their substrate specificity towards β-keratin remain unclear due to difficulties in preparing a soluble feather keratin substrate for use in activity assays. In the present study, we overexpressed Gallus gallus chromosomes 2 and 27 β-keratin-encoding genes in Escherichia coli, purified denatured recombinant proteins by Ni2+ affinity chromatography, and refolded by stepwise dialysis to yield soluble keratins...
2017: PloS One
https://www.readbyqxmd.com/read/28195032/ph-responsive-carriers-for-oral-drug-delivery-challenges-and-opportunities-of-current-platforms
#18
REVIEW
Lin Liu, WenDong Yao, YueFeng Rao, XiaoYang Lu, JianQing Gao
Oral administration is a desirable alternative of parenteral administration due to the convenience and increased compliance to patients, especially for chronic diseases that require frequent administration. The oral drug delivery is a dynamic research field despite the numerous challenges limiting their effective delivery, such as enzyme degradation, hydrolysis and low permeability of intestinal epithelium in the gastrointestinal (GI) tract. pH-Responsive carriers offer excellent potential as oral therapeutic systems due to enhancing the stability of drug delivery in stomach and achieving controlled release in intestines...
November 2017: Drug Delivery
https://www.readbyqxmd.com/read/28188936/cultivation-of-podospora-anserina-on-soybean-hulls-results-in-an-efficient-enzyme-cocktail-for-plant-biomass-hydrolysis
#19
Miia R Mäkelä, Ourdia Bouzid, Diogo Robl, Harm Post, Mao Peng, Albert Heck, Maarten Altelaar, Ronald P de Vries
The coprophilic ascomycete fungus Podospora anserina was cultivated on three different plant biomasses, i.e. cotton seed hulls (CSH), soybean hulls (SBH) and acid-pretreated wheat straw (WS) for four days, and the potential of the produced enzyme mixtures was compared in the enzymatic saccharification of the corresponding lignocellulose feedstocks. The enzyme cocktail P. anserina produced after three days of growth on SBH showed superior capacity to release reducing sugars from all tested plant biomass feedstocks compared to the enzyme mixtures from CSH and WS cultures...
February 7, 2017: New Biotechnology
https://www.readbyqxmd.com/read/28170227/analyte-responsive-hydrogels-intelligent-materials-for-biosensing-and-drug-delivery
#20
Heidi R Culver, John R Clegg, Nicholas A Peppas
Nature has mastered the art of molecular recognition. For example, using synergistic non-covalent interactions, proteins can distinguish between molecules and bind a partner with incredible affinity and specificity. Scientists have developed, and continue to develop, techniques to investigate and better understand molecular recognition. As a consequence, analyte-responsive hydrogels that mimic these recognitive processes have emerged as a class of intelligent materials. These materials are unique not only in the type of analyte to which they respond but also in how molecular recognition is achieved and how the hydrogel responds to the analyte...
February 7, 2017: Accounts of Chemical Research
keyword
keyword
59072
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"