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https://www.readbyqxmd.com/read/28203522/mass-spectral-determination-of-phosphopantetheinylation-specificity-for-carrier-proteins-in-mycobacterium-tuberculosis
#1
James Jung, Ghader Bashiri, Jodie M Johnston, Edward N Baker
Phosphopantetheinyl transferases (PPTases) are key elements in the modular syntheses performed by multienzyme systems such as polyketide synthases. PPTases transfer phosphopantetheine derivatives from Coenzyme A to carrier proteins (CPs), thus orchestrating substrate supply. We describe an efficient mass spectrometry-based protocol for determining CP specificity for a particular PPTase in organisms possessing several candidate PPTases. We show that the CPs MbtL and PpsC, both involved in synthesis of essential metabolites in Mycobacterium tuberculosis, are exclusively activated by the type 2 PPTase PptT and not the type 1 AcpS...
December 2016: FEBS Open Bio
https://www.readbyqxmd.com/read/28187530/structural-and-dynamic-characterization-of-a-freestanding-acyl-carrier-protein-involved-in-the-biosynthesis-of-cyclic-lipopeptide-antibiotics
#2
Subrata Paul, Hiroaki Ishida, Leonard T Nguyen, Zhihong Liu, Hans J Vogel
Friulimicin is a cyclic lipodecapeptide antibiotic that is produced by Actinoplanes friuliensis. Like the related lipopeptide drug daptomycin, the peptide skeleton of friulimicin is synthesized by a large multienzyme Nonribosomal Peptide Synthetase (NRPS) system. The LipD protein plays a major role in the acylation reaction of friulimicin. The attachment of the fatty acid group promotes its antibiotic activity. Phylogenetic analysis reveals that LipD is most closely related to other freestanding Acyl Carrier Proteins (ACPs), for which the genes are located near to NRPS gene clusters...
February 10, 2017: Protein Science: a Publication of the Protein Society
https://www.readbyqxmd.com/read/28181062/progress-in-biocatalysis-with-immobilized-viable-whole-cells-systems-development-reaction-engineering-and-applications
#3
REVIEW
Milan Polakovič, Juraj Švitel, Marek Bučko, Jaroslav Filip, Vilém Neděla, Marion B Ansorge-Schumacher, Peter Gemeiner
Viable microbial cells are important biocatalysts in the production of fine chemicals and biofuels, in environmental applications and also in emerging applications such as biosensors or medicine. Their increasing significance is driven mainly by the intensive development of high performance recombinant strains supplying multienzyme cascade reaction pathways, and by advances in preservation of the native state and stability of whole-cell biocatalysts throughout their application. In many cases, the stability and performance of whole-cell biocatalysts can be highly improved by controlled immobilization techniques...
February 8, 2017: Biotechnology Letters
https://www.readbyqxmd.com/read/28159788/revisiting-the-regulation-of-the-primary-scaffoldin-gene-in-clostridium-thermocellum
#4
Lizett Ortiz de Ora, Iván Muñoz-Gutiérrez, Edward A Bayer, Yuval Shoham, Raphael Lamed, Ilya Borovok
: Cellulosomes are considered to be one of the most efficient systems for degradation of plant cell-wall polysaccharides. The central cellulosome component comprises a large, noncatalytic, protein subunit called scaffoldin. Multiple saccharolytic enzymes are incorporated into the scaffoldins via specific high-affinity cohesin-dockerin interactions. Recently, the regulation of genes encoding certain cellulosomal components by multiple RNA polymerase alternative σ(I) factors has been demonstrated in Clostridium (Ruminiclostridium) thermocellum In the present report, we provide experimental evidence demonstrating that the C...
February 3, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/28138383/systematic-chemoenzymatic-synthesis-of-o-sulfated-sialyl-lewis-x-antigens
#5
Abhishek Santra, Hai Yu, Nova Tasnima, Musleh M Muthana, Yanhong Li, Jie Zeng, Nicholas J Kenyond, Angelique Y Louie, Xi Chen
O-Sulfated sialyl Lewis x antigens play important roles in nature. However, due to their structural complexity, they are not readily accessible by either chemical or enzymatic synthetic processes. Taking advantage of a bacterial sialyltransferase mutant that can catalyze the transfer of different sialic acid forms from the corresponding sugar nucleotide donors to Lewis x antigens which are fucosylated glycans as well as an efficient one-pot multienzyme (OPME) sialylation system, O-sulfated sialyl Lewis x antigens containing different sialic acid forms and O-sulfation at different locations were systematically synthesized by chemoenzymatic methods...
April 1, 2016: Chemical Science
https://www.readbyqxmd.com/read/28134951/converting-pasteurella-multocida-%C3%AE-2-3-sialyltransferase-1-pmst1-to-a-regioselective-%C3%AE-2-6-sialyltransferase-by-saturation-mutagenesis-and-regioselective-screening
#6
John B McArthur, Hai Yu, Jie Zeng, Xi Chen
A microtiter plate-based screening assay capable of determining the activity and regioselectivity of sialyltransferases was developed. This assay was used to screen two single-site saturation libraries of Pasteurella multocida α2-3-sialyltransferase 1 (PmST1) for α2-6-sialyltransferase activity and total sialyltransferase activity. PmST1 double mutant P34H/M144L was found to be the most effective α2-6-sialyltransferase and displayed 50% reduced donor hydrolysis and 50-fold reduced sialidase activity compared to the wild-type PmST1...
January 30, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28120367/photoelectrochemical-reduction-of-carbon-dioxide-to-methanol-through-a-highly-efficient-enzyme-cascade
#7
Su Keun Kuk, Raushan K Singh, Dong Heon Nam, Ranjitha Singh, Jung-Kul Lee, Chan Beum Park
Natural photosynthesis is an effective route for the clean and sustainable conversion of CO2 into high-energy chemicals. Inspired by the natural process, a tandem photoelectrochemical (PEC) cell with an integrated enzyme-cascade (TPIEC) system was designed, which transfers photogenerated electrons to a multienzyme cascade for the biocatalyzed reduction of CO2 to methanol. A hematite photoanode and a bismuth ferrite photocathode were applied to fabricate the iron oxide based tandem PEC cell for visible-light-assisted regeneration of the nicotinamide cofactor (NADH)...
January 25, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28107425/using-an-inducible-promoter-of-a-gene-encoding-penicillium-verruculosum-glucoamylase-for-production-of-enzyme-preparations-with-enhanced-cellulase-performance
#8
Alexander G Bulakhov, Pavel V Volkov, Aleksandra M Rozhkova, Alexander V Gusakov, Vitaly A Nemashkalov, Aidar D Satrutdinov, Arkady P Sinitsyn
BACKGROUND: Penicillium verruculosum is an efficient producer of highly active cellulase multienzyme system. One of the approaches for enhancing cellulase performance in hydrolysis of cellulosic substrates is to enrich the reaction system with β -glucosidase and/or accessory enzymes, such as lytic polysaccharide monooxygenases (LPMO) displaying a synergism with cellulases. RESULTS: Genes bglI, encoding β-glucosidase from Aspergillus niger (AnBGL), and eglIV, encoding LPMO (formerly endoglucanase IV) from Trichoderma reesei (TrLPMO), were cloned and expressed by P...
2017: PloS One
https://www.readbyqxmd.com/read/27925306/graphene-oxide-based-enzyme-nanoarchitectonics-for-substrate-channeling
#9
Motilal Mathesh, Jingquan Liu, Colin J Barrow, Wenrong Yang
The controlled spatial organization or compartmentalization of multi-enzyme cascade reactions to transfer a substrate from one enzyme to another for substrate channeling on scaffolds has sparked increasing interest in recent years. Here, we use graphene oxides to study the dependence of the activity of cascade reactions in a closely packed, randomly immobilized enzyme system on a 2 D scaffold. We first observe that the hydrophobicity of graphene oxides and various enzyme architectures for co-immobilized systems are important attributes for achieving high product-conversion rates...
December 7, 2016: Chemistry: a European Journal
https://www.readbyqxmd.com/read/27806579/cerium-oxide-based-nanozymes-redox-phenomenon-at-biointerfaces
#10
Sanjay Singh
Cerium oxide nanoparticles (nanoceria) are known to exhibit enzymelike activity, such as biological catalase, oxidase, superoxide dismutase, and peroxidase enzymelike activities. Catalytically active nanoceria offer several advantages over natural enzymes, such as controlled synthesis at low cost, tunable catalytic activities, as well as high stability against stringent physiological conditions. Exploiting these properties, several biomedical applications, such as biosensing, immunoassay, drug delivery, radiation protection, and tissue engineering, have been maneuvered...
November 2, 2016: Biointerphases
https://www.readbyqxmd.com/read/27759119/enzymatic-diversity-of-the-clostridium-thermocellum-cellulosome-is-crucial-for-the-degradation-of-crystalline-cellulose-and-plant-biomass
#11
Katsuaki Hirano, Masahiro Kurosaki, Satoshi Nihei, Hiroki Hasegawa, Suguru Shinoda, Mitsuru Haruki, Nobutaka Hirano
The cellulosome is a supramolecular multienzyme complex comprised of a wide variety of polysaccharide-degrading enzymes and scaffold proteins. The cellulosomal enzymes that bind to the scaffold proteins synergistically degrade crystalline cellulose. Here, we report in vitro reconstitution of the Clostridium thermocellum cellulosome from 40 cellulosomal components and the full-length scaffoldin protein that binds to nine enzyme molecules. These components were each synthesized using a wheat germ cell-free protein synthesis system and purified...
October 19, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27736072/sequential-one-pot-multienzyme-chemoenzymatic-synthesis-of-glycosphingolipid-glycans
#12
Hai Yu, Yanhong Li, Jie Zeng, Vireak Thon, Dung M Nguyen, Thao Ly, Hui Yu Kuang, Alice Ngo, Xi Chen
Glycosphingolipids are a diverse family of biologically important glycolipids. In addition to variations on the lipid component, more than 300 glycosphingolipid glycans have been characterized. These glycans are directly involved in various molecular recognition events. Several naturally occurring sialic acid forms have been found in sialic acid-containing glycosphingolipids, namely gangliosides. However, ganglioside glycans containing less common sialic acid forms are currently not available. Herein, highly effective one-pot multienzyme (OPME) systems are used in sequential for high-yield and cost-effective production of glycosphingolipid glycans, including those containing different sialic acid forms such as N-acetylneuraminic acid (Neu5Ac), N-glycolylneuraminic acid (Neu5Gc), 2-keto-3-deoxy-d-glycero-d-galacto-nononic acid (Kdn), and 8-O-methyl-N-acetylneuraminic acid (Neu5Ac8OMe)...
November 18, 2016: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/27720939/differential-expression-of-micrornas-from-mir-17-family-in-the-cerebellum-of-mucopolysaccharidosis-type-i-mice
#13
Vanessa Gonçalves Pereira, Matheus Trovão Queiroz, Vânia D'Almeida
Mucopolysaccharidosis type I (MPS I) is caused by deficiency of α-l-iduronidase, involved in degradation of glycosaminoglycans. Clinical manifestations are widely variable and patients with severe phenotype present developmental delay and cognitive decline, among other systemic alterations. MPS I patients present secondary accumulation of gangliosides in neuronal cells, besides accumulation of undegraded glycosaminoglycans. Reduction of Neu1 expression has been previously observed in the cerebellum of MPS I mice; to be active, neuraminidase 1 forms the lysosomal multienzyme complex (LMC) with two other proteins, β-galactosidase and protective protein/cathepsin A, involved in stepwise degradation of gangliosides in the lysosomes...
December 31, 2016: Gene
https://www.readbyqxmd.com/read/27624811/a-rapid-and-efficient-luminescence-based-method-for-assaying-phosphoglycosyltransferase-enzymes
#14
Debasis Das, Marthe T C Walvoort, Vinita Lukose, Barbara Imperiali
Phosphoglycosyltransferases (PGTs) are families of integral membrane proteins with intriguingly diverse architectures. These enzymes function to initiate many important biosynthetic pathways including those leading to peptidoglycan, N-linked glycoproteins and lipopolysaccharide O-antigen. In spite of tremendous efforts, characterization of these enzymes remains a challenge not only due to the inherent difficulties associated with the purification of integral membrane proteins but also due to the limited availability of convenient assays...
September 14, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27621442/toward-combined-delignification-and-saccharification-of-wheat-straw-by-a-laccase-containing-designer-cellulosome
#15
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
https://www.readbyqxmd.com/read/27539253/digestive-proteolysis-in-the-colorado-potato-beetle-leptinotarsa-decemlineata-activity-based-profiling-and-imaging-of-a-multipeptidase-network
#16
Jaroslav Srp, Martina Nussbaumerová, Martin Horn, Michael Mareš
The Colorado potato beetle (CPB), Leptinotarsa decemlineata, is a major pest of potato plants, and its digestive system is a promising target for development of pest control strategies. This work focuses on functional proteomic analysis of the digestive proteolytic enzymes expressed in the CPB gut. We identified a set of peptidases using imaging with specific activity-based probes and activity profiling with selective substrates and inhibitors. The secreted luminal peptidases were classified as: (i) endopeptidases of cathepsin D, cathepsin L, and trypsin types and (ii) exopeptidases with aminopeptidase (cathepsin H), carboxypeptidase (serine carboxypeptidase, prolyl carboxypeptidase), and carboxydipeptidase (cathepsin B) activities...
November 2016: Insect Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/27493686/enhancement-of-cellulosome-mediated-deconstruction-of-cellulose-by-improving-enzyme-thermostability
#17
Sarah Moraïs, Johanna Stern, Amaranta Kahn, Anastasia P Galanopoulou, Shahar Yoav, Melina Shamshoum, Matthew A Smith, Dimitris G Hatzinikolaou, Frances H Arnold, Edward A Bayer
BACKGROUND: The concerted action of three complementary cellulases from Clostridium thermocellum, engineered to be stable at elevated temperatures, was examined on a cellulosic substrate and compared to that of the wild-type enzymes. Exoglucanase Cel48S and endoglucanase Cel8A, both key elements of the natural cellulosome from this bacterium, were engineered previously for increased thermostability, either by SCHEMA, a structure-guided, site-directed protein recombination method, or by consensus-guided mutagenesis combined with random mutagenesis using error-prone PCR, respectively...
2016: Biotechnology for Biofuels
https://www.readbyqxmd.com/read/27450681/encapsulation-of-multiple-cargo-proteins-within-recombinant-eut-nanocompartments
#18
Maureen B Quin, Sarah A Perdue, Szu-Yi Hsu, Claudia Schmidt-Dannert
Spatial organization via encapsulation of enzymes within recombinant nanocompartments may increase efficiency in multienzyme cascades. Previously, we reported the encapsulation of single cargo proteins within nanocompartments in the heterologous host Escherichia coli. This was achieved by coexpression of the Salmonella enterica LT2 ethanolamine utilization bacterial microcompartment shell proteins EutS or EutSMNLK, with a signal sequence EutC1-19 cargo protein fusion. Optimization of this system, leading to the targeting of more than one cargo protein, requires an understanding of the encapsulation mechanism...
November 2016: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/27298375/complexity-of-the-ruminococcus-flavefaciens-cellulosome-reflects-an-expansion-in-glycan-recognition
#19
Immacolata Venditto, Ana S Luis, Maja Rydahl, Julia Schückel, Vânia O Fernandes, Silvia Vidal-Melgosa, Pedro Bule, Arun Goyal, Virginia M R Pires, Catarina G Dourado, Luís M A Ferreira, Pedro M Coutinho, Bernard Henrissat, J Paul Knox, Arnaud Baslé, Shabir Najmudin, Harry J Gilbert, William G T Willats, Carlos M G A Fontes
The breakdown of plant cell wall (PCW) glycans is an important biological and industrial process. Noncatalytic carbohydrate binding modules (CBMs) fulfill a critical targeting function in PCW depolymerization. Defining the portfolio of CBMs, the CBMome, of a PCW degrading system is central to understanding the mechanisms by which microbes depolymerize their target substrates. Ruminococcus flavefaciens, a major PCW degrading bacterium, assembles its catalytic apparatus into a large multienzyme complex, the cellulosome...
June 28, 2016: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/27104227/human-pyruvate-dehydrogenase-complex-e2-and-e3bp-core-subunits-new-models-and-insights-from-molecular-dynamics-simulations
#20
Samira Hezaveh, An-Ping Zeng, Uwe Jandt
Targeted manipulation and exploitation of beneficial properties of multienzyme complexes, especially for the design of novel and efficiently structured enzymatic reaction cascades, require a solid model understanding of mechanistic principles governing the structure and functionality of the complexes. This type of system-level and quantitative knowledge has been very scarce thus far. We utilize the human pyruvate dehydrogenase complex (hPDC) as a versatile template to conduct corresponding studies. Here we present new homology models of the core subunits of the hPDC, namely E2 and E3BP, as the first time effort to elucidate the assembly of hPDC core based on molecular dynamic simulation...
May 19, 2016: Journal of Physical Chemistry. B
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