Read by QxMD icon Read

enzyme engineering

Kimberly McCoy, Masaki Uchida, Byeongdu Lee, Trevor Douglas
Bottom-up construction of mesoscale materials using biologically derived nanoscale building blocks enables engineering of desired physical properties using green production methods. Virus-like particles (VLPs) are exceptional building blocks due to their monodispersed sizes, geometric shapes, production ease, proteinaceous composition, and our ability to independently functionalize the interior and exterior interfaces. Here a VLP, derived from bacteriophage P22, is used as a building block for the fabrication of a Protein Macromolecular Framework (PMF); a tightly-linked 3D network of functional protein cages that exhibit long-range order and catalytic activity...
March 20, 2018: ACS Nano
Ruoxing Lei, Jessica P Lee, Matthew B Francis, Sanjay Kumar
Intrinsically disordered proteins (IDPs) play central roles in numerous cellular processes. While IDP structure and function are often regulated by multisite phosphorylation, the biophysical mechanisms linking these post-translational modifications to IDP structure remain elusive. For example, the intrinsically disordered C-terminal sidearm domain of the neurofilament heavy subunit (NFH-SA) forms a dense brush along axonal NF backbones and is subject to extensive serine phosphorylation. Yet, biophysical insight into the relationship between phosphorylation and structure has been limited by the lack of paradigms in which NF brush conformational responses can be measured in the setting of controlled phosphorylation...
March 20, 2018: Biochemistry
Shweta D Dabhi, Basant Roondhe, Prafulla K Jha
Understanding the interactions between biomolecules and boron nitride nanostructures is key for their use in nanobiotechnology and medical engineering. In this study, we investigated the adsorption of nucleobases adenine (A), guanine (G), cytosine (C), thymine (T) and uracil (U) over armchair and zigzag boron nitride nanoribbons (BNNR) using density functional theory to define the applicability of BNNR for the sensing of nucleobases and DNA sequencing. To appropriately account for dispersion, the van der Waals forces (DFT-D2)-type method developed by Grimme was also included in the calculations...
March 20, 2018: Physical Chemistry Chemical Physics: PCCP
Nizaá Jiménez-Arroyo, Paloma C Gil-Rodríguez, Adelaida Díaz-Vilchis, Sonia P Rojas-Trejo, Enrique Rudiño-Piñera
Understanding Peroxidase (PRXs) enzymatic diversity and functional significance from a three-dimensional point of view is a key point for structural and mechanistic studies. In this context, Zo-peroxidase (ZoPrx) a member of the class III peroxidases and secreted by plants, differs from all previously described PRXs because of its remarkable catalytic stability in the presence of hydrogen peroxide. In this work, we present the crystallographic structure of ZoPrx isolated from Japanese radish, at 2.05 Å resolution...
March 2018: Biochemistry and Biophysics Reports
Günseli Kurt-Gür, Emel Ordu
NAD+ -dependent formate dehydrogenases (FDH, EC, providing energy to the cell in methylotrophic microorganisms, are stress proteins in higher plants and the level of FDH expression increases under several abiotic and biotic stress conditions. They are biotechnologically important enzymes in NAD(P)H regeneration as well as CO2 reduction. Here, the truncated form of the Gossypium hirsutum fdh1 cDNA was cloned into pQE-2 vector, and overexpressed in Escherichia coli DH5α-T1 cells. Recombinant GhFDH1 was purified 26...
March 2018: 3 Biotech
T Einfalt, D Witzigmann, C Edlinger, S Sieber, R Goers, A Najer, M Spulber, O Onaca-Fischer, J Huwyler, C G Palivan
Despite tremendous efforts to develop stimuli-responsive enzyme delivery systems, their efficacy has been mostly limited to in vitro applications. Here we introduce, by using an approach of combining biomolecules with artificial compartments, a biomimetic strategy to create artificial organelles (AOs) as cellular implants, with endogenous stimuli-triggered enzymatic activity. AOs are produced by inserting protein gates in the membrane of polymersomes containing horseradish peroxidase enzymes selected as a model for natures own enzymes involved in the redox homoeostasis...
March 19, 2018: Nature Communications
Antonella Caforio, Melvin F Siliakus, Marten Exterkate, Samta Jain, Varsha R Jumde, Ruben L H Andringa, Servé W M Kengen, Adriaan J Minnaard, Arnold J M Driessen, John van der Oost
One of the main differences between bacteria and archaea concerns their membrane composition. Whereas bacterial membranes are made up of glycerol-3-phosphate ester lipids, archaeal membranes are composed of glycerol-1-phosphate ether lipids. Here, we report the construction of a stable hybrid heterochiral membrane through lipid engineering of the bacterium Escherichia coli By boosting isoprenoid biosynthesis and heterologous expression of archaeal ether lipid biosynthesis genes, we obtained a viable E. coli strain of which the membranes contain archaeal lipids with the expected stereochemistry...
March 19, 2018: Proceedings of the National Academy of Sciences of the United States of America
Taylor C Stevenson, Colette Cywes-Bentley, Tyler D Moeller, Kevin B Weyant, David Putnam, Yung-Fu Chang, Bradley D Jones, Gerald B Pier, Matthew P DeLisa
Many microbial pathogens produce a β-(1→6)-linked poly- N -acetyl-d-glucosamine (PNAG) surface capsule, including bacterial, fungal, and protozoan cells. Broadly protective immune responses to this single conserved polysaccharide antigen in animals are possible but only when a deacetylated poly- N -acetyl-d-glucosamine (dPNAG; <30% acetate) glycoform is administered as a conjugate to a carrier protein. Unfortunately, conventional methods for natural extraction or chemical synthesis of dPNAG and its subsequent conjugation to protein carriers can be technically demanding and expensive...
March 19, 2018: Proceedings of the National Academy of Sciences of the United States of America
Haofeng Gao, Chanjuan Li, Ramesh Bandikari, Ziduo Liu, Nan Hu, Qiang Yong
BACKGROUND: In industries lipolytic reactions occur in insensitive conditions such as high temperature thus novel stout esterases with unique properties are attracts to the industrial application. Protein engineering is the tool to obtain desirable characters of enzymes. A novel esterase gene was isolated from South China Sea and subjected to a random mutagenesis and site directed mutagenesis for higher activity and thermo-stability compared to wild type. RESULTS: A novel esterase showed the highest hydrolytic activity against p-nitrophenyl acetate (pNPA, C2) and the optimal activity at 40 °C and pH 8...
March 19, 2018: Microbial Cell Factories
Julie Kovářová, Andrew W Pountain, David Wildridge, Stefan Weidt, Frédéric Bringaud, Richard J S Burchmore, Fiona Achcar, Michael P Barrett
Transketolase (TKT) is part of the non-oxidative branch of the pentose phosphate pathway (PPP). Here we describe the impact of removing this enzyme from the pathogenic protozoan Leishmania mexicana. Whereas the deletion had no obvious effect on cultured promastigote forms of the parasite, the Δtkt cells were not infective to mice. Δtkt promastigotes were more susceptible to oxidative stress and various leishmanicidal drugs than wild-type, and metabolomics analysis revealed profound changes to metabolism in these cells...
March 19, 2018: PLoS Pathogens
Jaime Agudo-Canalejo, Pierre Illien, Ramin Golestanian
Chemotaxis of enzymes in response to gradients in the concentration of their substrate has been widely reported in recent experiments, but a basic understanding of the process is still lacking. Here, we develop a microscopic theory for chemotaxis, valid for enzymes and other small molecules. Our theory includes both non-specific interactions between enzyme and substrate, as well as complex formation through specific binding between the enzyme and the substrate. We find that two distinct mechanisms contribute to enzyme chemotaxis: a diffusiophoretic mechanism due to the non-specific interactions, and a new type of mechanism due to binding-induced changes in the diffusion coefficient of the enzyme...
March 19, 2018: Nano Letters
Meng-Die Qi, Jian Wang, Xiao-Jing Ma, Quan Zhang, Fang-Fang Wang, Ying Kang, Hui-Xin Lin, Yong Liu
Andrographolide is a main active ingredient in traditional Chinese medicine Andrographis paniculata,with a variety of pharmacological activity,widely used in clinical practice. However its biosynthetic pathway has not been resolved. Cytochrome P450 reductase provides electrons for CYP450 and plays an important role in the CYP450 catalytic process. In this study,the coding sequence of A. paniculata CPR was screened and cloned by homologous alignment,named ApCPR4. The ApCPR4 protein was obtained by prokaryotic expression...
January 2018: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
Jian Zha, Mattheos A G Koffas
Microbial production of plant-derived natural products by engineered microorganisms has achieved great success thanks to large extend to metabolic engineering and synthetic biology. Anthocyanins, the water-soluble colored pigments found in terrestrial plants that are responsible for the red, blue and purple coloration of many flowers and fruits, are extensively used in food and cosmetics industry; however, their current supply heavily relies on complex extraction from plant-based materials. A promising alternative is their sustainable production in metabolically engineered microbes...
December 2017: Synthetic and Systems Biotechnology
Lin Wang, Satyakam Dash, Chiam Yu Ng, Costas D Maranas
Metabolic pathways reflect an organism's chemical repertoire and hence their elucidation and design have been a primary goal in metabolic engineering. Various computational methods have been developed to design novel metabolic pathways while taking into account several prerequisites such as pathway stoichiometry, thermodynamics, host compatibility, and enzyme availability. The choice of the method is often determined by the nature of the metabolites of interest and preferred host organism, along with computational complexity and availability of software tools...
December 2017: Synthetic and Systems Biotechnology
Jayanna N Banavath, Thammineni Chakradhar, Varakumar Pandit, Sravani Konduru, Krishna K Guduru, Chandra S Akila, Sudhakar Podha, Chandra O R Puli
Peanut is an important oilseed and food legume cultivated as a rain-fed crop in semi-arid tropics. Drought and high salinity are the major abiotic stresses limiting the peanut productivity in this region. Development of drought and salt tolerant peanut varieties with improved yield potential using biotechnological approach is highly desirable to improve the peanut productivity in marginal geographies. As abiotic stress tolerance and yield represent complex traits, engineering of regulatory genes to produce abiotic stress-resilient transgenic crops appears to be a viable approach...
2018: Frontiers in Chemistry
Silvana Konermann, Peter Lotfy, Nicholas J Brideau, Jennifer Oki, Maxim N Shokhirev, Patrick D Hsu
Class 2 CRISPR-Cas systems endow microbes with diverse mechanisms for adaptive immunity. Here, we analyzed prokaryotic genome and metagenome sequences to identify an uncharacterized family of RNA-guided, RNA-targeting CRISPR systems that we classify as type VI-D. Biochemical characterization and protein engineering of seven distinct orthologs generated a ribonuclease effector derived from Ruminococcus flavefaciens XPD3002 (CasRx) with robust activity in human cells. CasRx-mediated knockdown exhibits high efficiency and specificity relative to RNA interference across diverse endogenous transcripts...
March 8, 2018: Cell
Sarene Koh, Janine Kah, Christine Y L Tham, Ninghan Yang, Erica Ceccarello, Adeline Chia, Margaret Chen, Atefeh Khakpoor, Andrea Pavesi, Anthony T Tan, Maura Dandri, Antonio Bertoletti
BACKGROUND & AIMS: Strategies to develop virus-specific T cells against hepatic viral infections have been hindered by safety concerns. We engineered non-lytic human T cells to suppress replication of hepatitis B virus (HBV) and hepatitis C virus (HCV) without overt hepatotoxicity, and investigated their antiviral activity. METHODS: We electroporated resting T cells or T cells activated by anti-CD3 with mRNAs encoding HBV or HCV-specific T-cell receptors (TCRs) to create 2 populations of TCR-reprogrammed T cells...
March 14, 2018: Gastroenterology
Chen Geng, Tengfei Zhao, Chunxian Yang, Qiaozhuo Zhang, Feng Bai, Junlan Zeng, Fangyuan Zhang, Xiaoqiang Liu, Xiaozhong Lan, Min Chen, Zhihua Liao
N-methylputrescine is the precursor of nicotine and pharmaceutical tropane alkaloids such as hyoscyamine. Putrescine N-methyltransferase (PMT) catalyzes the N-methylation of putrescine to form N-methylputrescine. While the role of PMT in nicotine biosynthesis is clear, knowledge of PMT in the biosynthesis of tropane alkaloids (TAs) and the regulation of polyamines remains limited. We characterized a PMT gene from Hyoscyamus niger, designated HnPMT that was specifically expressed in roots, especially in the secondary roots and dramatically induced by methyl jasmonate (MeJA)...
March 2, 2018: Plant Physiology and Biochemistry: PPB
Xinjian Yin, Jianping Wu, Lirong Yang
The objective of this study was to identify and exploit a robust biocatalyst that can be applied in reductive amination for enantioselective synthesis of the competitive herbicide L-phosphinothricin. Applying a genome mining-based library construction strategy, eight NADPH-specific glutamate dehydrogenases (GluDHs) were identified for reductively aminating 2-oxo-4-[(hydroxy)(methyl)phosphinoyl]butyric acid (PPO) to L-phosphinothricin. Among them, the glutamate dehydrogenase cloned from Pseudomonas putida (PpGluDH) exhibited relatively high catalytic activity and favorable soluble expression...
March 16, 2018: Applied Microbiology and Biotechnology
Marika Ziesack, Nathan Rollins, Aashna Shah, Brendon Dusel, Gordon Webster, Pamela A Silver, Jeffrey C Way
Medium-chain fatty acids are commodity chemicals. Increasing and modifying the activity of thioesterases (TEs) on medium chain fatty acyl-ACP esters may enable high yield microbial production of these molecules. The plant Cuphea palustris harbors two distinct TEs: Cp FatB1 (C8 -specificity, lower activity) and Cp FatB2 (C14 -specificity, higher activity) with 78% sequence identity. We combined structural features from these two enzymes to create several chimeric TEs, some of which showed non-natural fatty acid production as measured by an enzymatic assay and GC-MS...
March 16, 2018: Applied and Environmental Microbiology
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"