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membrane protein purification

V Vasilca, A Sadeghpour, S Rawson, L E Hawke, S A Baldwin, T Wilkinson, D Bannister, V L G Postis, M Rappolt, S P Muench, L J C Jeuken
Screening assays performed against membrane protein targets (e.g. phage display) are hampered by issues arising from protein expression and purification, protein stability in detergent solutions and epitope concealment by detergent micelles. Here, we have studied a fast and simple method to improve screening against membrane proteins: spherical-supported bilayer lipid membranes ("SSBLM"). SSBLMs can be quickly isolated via low-speed centrifugation and redispersed in liquid solutions while presenting the target protein in a native-like lipid environment...
March 12, 2018: Analytical Biochemistry
Ingo de Vries, Sarah Schreiber, Daniel Boßmann, Zawadi Hellmann, Jens Kopatz, Harald Neumann, Sascha Beutel
Polysialic acid (polySia) is a promising molecule for various medical applications (e.g., treatment of inflammatory neurodegenerative diseases). In this study a complete production process for human-identical α-(2,8)-linked polySia was developed using a disposable bioreactor for cultivation of Escherichia coli K1 and single-use membrane adsorbers for downstream processing (DSP). The cultivation process was optimized to minimize complex media components and a maturation process after cultivation was established...
March 2018: Biotechnology Reports
Maciek Adamowski, Madhumitha Narasimhan, Urszula Kania, Matouš Glanc, Geert De Jaeger, Jiří Friml
Clathrin-mediated endocytosis (CME) is a cellular trafficking process in which cargoes and lipids are internalized from the plasma membrane into vesicles coated with clathrin and adaptor proteins. CME is essential for many developmental and physiological processes in plants, but its underlying mechanism is not well characterised compared to that in yeast and animal systems. Here, we searched for new factors involved in CME in Arabidopsis thaliana by performing Tandem Affinity Purification of proteins that interact with clathrin light chain, a principal component of the clathrin coat...
March 6, 2018: Plant Cell
Caroline Serino-Silva, Karen Morais-Zani, Marcos Hikari Toyama, Daniela de Oliveira Toyama, Henrique Hessel Gaeta, Caroline Fabri Bittencourt Rodrigues, Wéslei da Silva Aguiar, Alexandre Keiji Tashima, Kathleen Fernandes Grego, Anita Mitico Tanaka-Azevedo
Phospholipases A2 (PLA2) are enzymes acting on the cell membrane phospholipids resulting in fatty acids and lysophospholipids and deconstructing the cell membrane. This protein is commonly found in snake venoms, causing tissue inflammation in the affected area. Evidence indicates that snakes have natural resistance to their own venom due to protective properties in plasma, that inhibit the action of proteins present in their venom. Given that, this study aimed to purify and characterize a γPLI from Bothrops jararaca serum, named γBjPLI...
2018: PloS One
Prasannan V Anu, Madathiparambil G Madanan, Ananthakrishnan J Nair, Gangaprasad A Nair, Govinda Pillai M Nair, Perumana R Sudhakaran, Padikara K Satheeshkumar
Oligopeptidases are enzymes involved in the degradation of short peptides (generally less than 30 amino acids in size) which help pathogens evade the host defence mechanisms. Leptospira is a zoonotic pathogen and causes leptospirosis in mammals. Proteome analysis of Leptospira revealed the presence of oligopeptidase A (OpdA) among other membrane proteins. To study the role of oligopeptidase in leptospirosis, the OpdA of L. interrogans was cloned and expressed in Escherichia coli with a histidine tag (His-tag)...
March 3, 2018: Molecular Biotechnology
Yang Ji, Yuan Lu, Yishu Yan, Xinxin Liu, Nan Su, Chong Zhang, Shengli Bi, Xin-Hui Xing
The Ebola hemorrhagic fever caused by Ebola virus is an extremely dangerous disease, and effective therapeutic agents are still lacking. Platforms for the efficient production of vaccines are crucial to ensure quick response against an Ebola virus outbreak. Ebolavirus glycoprotein (EbolaGP) on the virion surface is responsible for membrane binding and virus entry, thus becoming the key target for vaccine development. However, heterologous expression of this protein still faces engineering challenges such as low production levels and insoluble aggregation...
March 3, 2018: Biotechnology Journal
Raika Yamagiwa, Takuya Kurahashi, Mariko Takeda, Mayuho Adachi, Hiro Nakamura, Hiroyuki Arai, Yoshitsugu Shiro, Hitomi Sawai, Takehiko Tosha
Membrane-integrated nitric oxide reductase (NOR) reduces nitric oxide (NO) to nitrous oxide (N2 O) with protons and electrons. This process is essential for the elimination of the cytotoxic NO that is produced from nitrite (NO2 - ) during microbial denitrification. A structure-guided mutagenesis of NOR is required to elucidate the mechanism for NOR-catalyzed NO reduction. We have already solved the crystal structure of cytochrome c-dependent NOR (cNOR) from Pseudomonas aeruginosa. In this study, we then constructed its expression system using cNOR-gene deficient and wild-type strains for further functional study...
February 27, 2018: Biochimica et Biophysica Acta
Farida Larit, Khaled M Elokely, Narayan D Chaurasiya, Samira Benyahia, Manal A Nael, Francisco León, Mohammad Sanad Abu-Darwish, Thomas Efferth, Yan-Hong Wang, Djamila Belouahem-Abed, Samir Benayache, Babu L Tekwani, Stephen J Cutler
BACKGROUND: Monoamine oxidases (MAOs) are outer mitochondrial membrane flavoenzymes. They catalyze the oxidative deamination of a variety of neurotransmitters. MAO-A and MAO-B may be considered as targets for inhibitors to treat neurodegenerative diseases and depression and for managing symptoms associated with Parkinson's and Alzheimer's diseases. PURPOSE: The objective was to evaluate the inhibitory effect of Hypericum afrum and Cytisus villosus against MAO-A and B and to isolate the compounds responsible for the MAO-inhibitory activity...
February 1, 2018: Phytomedicine: International Journal of Phytotherapy and Phytopharmacology
Setsuko Komatsu, Akiko Hashiguchi
Soybean, which is rich in protein and oil, is cultivated in several climatic zones; however, its growth is markedly decreased by flooding. Proteomics is a useful tool for understanding the flooding-response mechanism in soybean. Subcellular proteomics has the potential to elucidate localized cellular responses and investigate communications among subcellular components during plant growth and during stress. Under flooding, proteins related to signaling, stress and the antioxidative system are increased in the plasma membrane; scavenging enzymes for reactive-oxygen species are suppressed in the cell wall; protein translation is suppressed through inhibition of proteins related to preribosome biogenesis and mRNA processing in the nucleus; levels of proteins involved in the electron transport chain are reduced in the mitochondrion; and levels of proteins related to protein folding are decreased in the endoplasmic reticulum...
February 27, 2018: Proteomes
Daehwan Kim, Seockmo Ku
One of the main challenges of using recombinant enzymes is that they are derived from genetically-modified microorganisms commonly located in the intracellular region. The use of these recombinant enzymes for commercial purposes requires the additional processes of cell disruption and purification, which may result in enzyme loss, denaturation, and increased total production cost. In this study, the cellulase gene of Bacillus licheniformis ATCC 14580 was cloned, over-expressed, and surface displayed in recombinant Escherichia coli using an ice-nucleation protein (INP)...
February 24, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Deepak B Thimiri Govinda Raj, Niamat Ali Khan
In this article, we elaborate the application of thermal decomposition based synthesis of Fe3 O4 superparamagnetic nanoparticle (SPMNP) in subcellular fractionation context. Here, we performed surface functionalization of SPMNP with phospholipids and dimercaptosuccinic acid. Surprisingly, we observed surface functionalization dependent SPMNP localization in subcellular compartments such as plasma membrane, endosomes and lysosomes. By using SPMNP based subcellular localization with pulse-chase methodology, we could use SPMNP for high pure-high yield organelle (plasma membrane, endosomes and lysosome) fractionation...
2018: Nano Convergence
Chang Seon Lee, Moon-Ki Choi, Ye Young Hwang, Hyunki Kim, Moon Ki Kim, Yun Jung Lee
Water purification by membranes is widely investigated to address concerns related to the scarcity of clean water. Achieving high flux and rejection simultaneously is a difficult challenge using such membranes because these properties are mutually exclusive in common artificial membranes. Nature has developed a method for this task involving water-channel membrane proteins known as aquaporins. Here, the design and fabrication of graphene oxide (GO)-based membranes with a surface-tethered peptide motif designed to mimic the water-selective filter of natural aquaporins is reported...
February 27, 2018: Advanced Materials
Janine Habier, Patrick May, Anna Heintz-Buschart, Anubrata Ghosal, Anke K Wienecke-Baldacchino, Esther N M Nolte-'t Hoen, Paul Wilmes, Joëlle V Fritz
Outer membrane vesicles (OMVs) are released by commensal as well as pathogenic Gram-negative bacteria. These vesicles contain numerous bacterial components, such as proteins, peptidoglycans, lipopolysaccharides, DNA, and RNA. To examine if OMV-associated RNA molecules are bacterial degradation products and/or are functionally active, it is necessary to extract RNA from pure OMVs for subsequent analysis. Therefore, we describe here an isolation method of ultrapure OMVs and the subsequent extraction of RNA and basic steps of RNA-Seq analysis...
2018: Methods in Molecular Biology
Ruth Skrzypek, Shagufta Iqbal, Richard Callaghan
Membrane proteins are notoriously difficult to investigate in isolation. The focus of this chapter is the key step following extraction and purification of membrane proteins; namely reconstitution. The process of reconstitution re-inserts proteins into a lipid bilayer that partly resembles their native environment. This native environment is vital to the stability of membrane proteins, ensuring that they undergo vital conformational transitions and maintain optimal interaction with their substrates. Reconstitution may take many forms and these have been classified into two broad categories...
February 15, 2018: Methods: a Companion to Methods in Enzymology
Nanao Suzuki, Yuuki Takamuku, Tomohiro Asakawa, Makoto Inai, Tomoya Hino, So Iwata, Toshiyuki Kan, Takeshi Murata
Membrane proteins, such as G-protein coupled receptors, control communication between cells and their environments and are indispensable for many cellular functions. Nevertheless, structural studies on membrane proteins lag behind those on water-soluble proteins, due to their low structural stability, making it difficult to obtain crystals for X-ray crystallography. Optimizing conditions to improve the stability of membrane proteins is essential for successful crystallization. However, the optimization usually requires large amounts of purified samples, and it is a time-consuming and trial-and-error process...
February 9, 2018: Analytical Biochemistry
Takuya Ogawa, Asako Tanaka, Jun Kawamoto, Tatsuo Kurihara
1-Acyl-sn-glycerol-3-phosphate acyltransferase (designated as PlsC in bacteria) catalyzes the acylation of lysophosphatidic acid and is responsible for the de novo production of phosphatidic acid, a precursor for the synthesis of various membrane glycerophospholipids. Because PlsC is an integral membrane protein, it is generally difficult to solubilize it without causing its inactivation, which has been hampering its biochemical characterization despite its ubiquitous presence and physiological importance. Most biochemical studies of PlsC have been carried out by using crude membrane preparations or intact cells...
February 5, 2018: Journal of Biochemistry
Petr Rathner, Michael Stadlbauer, Christoph Romanin, Marc Fahrner, Isabella Derler, Norbert Müller
We report a new NMR-scale purification procedure for two recombinant wild type fragments of the stromal interaction molecule 1 (STIM1). This protein acts as a calcium sensor in the endoplasmic reticulum (ER) and extends into the cytosol accumulating at ER - plasma membrane (PM) junctions upon calcium store depletion ultimately leading to activation of the Orai/CRAC channel. The functionally relevant cytosolic part of STIM1 consists of three coiled coil domains, which are mainly involved in intra- and inter-molecular homomeric interactions as well as coupling to and gating of CRAC channels...
February 1, 2018: Protein Expression and Purification
Mark T Agasid, Xuemin Wang, Yiding Huang, Colleen M Janczak, Robert Branström, S Scott Saavedra, Craig A Aspinwall
The inwardly rectifying K+ (Kir) channel, Kir6.2, plays critical roles in physiological processes in the brain, heart, and pancreas. Although Kir6.2 has been extensively studied in numerous expression systems, a comprehensive description of an expression and purification protocol has not been reported. We expressed and characterized a recombinant Kir6.2, with an N-terminal decahistidine tag, enhanced green fluorescent protein (eGFP) and deletion of C-terminal 26 amino acids, in succession, denoted eGFP-Kir6...
January 30, 2018: Protein Expression and Purification
Toktam Abbasnia, Ahmad Asoodeh, Gholamreza Habibi, Alireza Haghparast
BACKGROUND: Tropical theileriosis is widely distributed from North Africa to East Asia. It is a tick-borne disease caused by Theileria annulata, an obligate two-host intracellular protozoan parasite of cattle. Theileria annulata use leukocytes and red blood cells for completion of the life-cycle in mammalian hosts. The stage of Theileria annulata in monocytes and B lymphocytes of cattle is an important step in pathogenicity and diagnosis of the disease. Glycosylphosphatidylinositols (GPIs) are a distinct class of glycolipid structures found in eukaryotic cells and are implicated in several biological functions...
February 6, 2018: Parasites & Vectors
Carlo Guardiani, Andrea Magrì, Andonis Karachitos, Maria Carmela Di Rosa, Simona Reina, Igor Bodrenko, Angela Messina, Hanna Kmita, Matteo Ceccarelli, Vito De Pinto
The yeast Saccharomyces cerevisiae genome is endowed with two distinct isoforms of Voltage-Dependent Anion Channel (VDAC). The isoform yVDAC2 is currently understudied with respect to the best known yVDAC1. Yet, since the discovery, the function of yVDAC2 was unclear, leading to the hypothesis that it might be devoid of a channel function. In this work we have elucidated, by bioinformatics modeling and electrophysiological analysis, the functional activity of yVDAC2. The conformation of yVDAC2 and, for comparison, of yVDAC1 were modeled using a multiple template approach involving mouse, human and zebrafish structures and both showed to arrange the sequences as the typical 19-stranded VDAC β-barrel...
February 1, 2018: Biochimica et Biophysica Acta
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