Retinol binding protein IV purified from Escherichia coli using intein-mediated cleavage as a suitable replacement for serum sources

Publication date: Available online 19 November 2019Source: Protein Expression and PurificationAuthor(s): Chandler B. Est, Regina M. MurphyAbstractRetinol binding protein IV (RBP) functions as the principal carrier of retinol (Vitamin A) in the blood, where RBP circulates bound to another serum protein, transthyretin. Isolation of pure RBP from the transthyretin complex in human serum can be difficult, but expression of RBP in recombinant systems can circumvent these purification issues. Human recombinant RBP has previously been successfully expressed and purified from E. coli, but recovery of active protein typically requires extensive processing steps, such as denaturing and refolding, and complex purification steps, such as multi-modal chromatography. Furthermore, these methods produce recombinant proteins, often tagged, that display different functional and structural characteristics across systems. In this work, we optimized downstream processing by use of an intein-based expression system in E. coli to produce tag-free, human recombinant RBP (rRBP) with intact native amino termini at yields of up to ∼15 mg/L off column. The novel method requires solubilization of inclusion bodies and subsequent oxidative refolding in the presence of retinol, but importantly allows for one-step chromatographic purification that yields high purity rRBP with no N-terminal Met or other tag. Previously reported purification methods typically require two or more chromatographic separatio...
Source: Protein Expression and Purification - Category: Biochemistry Source Type: research

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Publication date: Available online 9 December 2019Source: Journal of ColoproctologyAuthor(s): Seyedeh Elham Norollahi, Seyed Mohammad Taghi Hamidian, Zeynab Khazaee Kohpar, Rezvan Azadi, Pooya Rostami, Sogand Vahidi, Sahar Ghazanfari, Farnaz Azar Shabe, Roya Khaksar, Ali Akbar SamadaniAbstractColorectal cancer is one of the most important malignancies in the classification of gastrointestinal cancers. One of the predisposing factors at molecular level for this cancer is via WNT signaling which is associated with the vast numbers of different genes. Thus, in this study, we aimed to investigate whether Adenomatous Polyposis ...
Source: Journal of Coloproctology - Category: Gastroenterology Source Type: research
We reported a general increase of unnecessary urine cultures in both community and hospital patients. The most representative microorganism isolated from Community (58.2%) and Hospital (47.6%) was E. coli. UTIs causative bacteria in hospitalized patients was more than twice as resistant to Trimetoprim/sulphamethoxazole (OR 2.26) and Imipenem (OR 2.56), for Gram-positive and Gram-negative, respectively, than in Community patients. Nitrofurantoin was the only agent without differences in resistance rate between community and hospital UTIs. Therefore, physicians could use it as a definitive therapy for uncomplicated cystitis ...
Source: New Microbiologica - Category: Microbiology Tags: New Microbiol Source Type: research
Authors: Rovida F, Nepita EV, Giardina F, Piralla A, Campanini G, Baldanti F Abstract About 15,000 hospitalizations due to group A Rotavirus gastroenteritis (RVA) are recorded each year in Italy. In the present study, we report the seasonal distribution and molecular characterization of RVA in pediatric and adult hospitalized patients in the period September 2015-April 2018 in Pavia province, Lombardy Region. During the study period, stool samples of 1450 patients with acute gastroenteritis were analyzed and 122 were RVA positive, the majority belonging to pediatric patients (94.0%) while only a minority of patient...
Source: New Microbiologica - Category: Microbiology Tags: New Microbiol Source Type: research
Authors: Kawanishi M, Hisatomi Y, Oda Y, Shimohara C, Tsunematsu Y, Sato M, Hirayama Y, Miyoshi N, Iwashita Y, Yoshikawa Y, Sugimura H, Mutoh M, Ishikawa H, Wakabayashi K, Yagi T, Watanabe K Abstract Colibactin is a polyketide-peptide genotoxin produced by enteric bacteria such as E. coli, and is considered to contribute to the development of colorectal cancer. We previously isolated E. coli strains from Japanese colorectal cancer patients, and in the present study we investigated the genotoxic potency of the colibactin-producing (clb+) E. coli strains that carry the polyketide synthases "pks" gene cluste...
Source: Journal of Toxicological Sciences - Category: Toxicology Tags: J Toxicol Sci Source Type: research
Publication date: Available online 10 December 2019Source: Progress in Biophysics and Molecular BiologyAuthor(s): Ambuj Kumar Kushwaha, Shashi BhushanAbstractProtein synthesis in all the living cells is mediated by a large protein-RNA complex called the ribosome. These macromolecular complexes can range from 2.5 (prokaryotes) to 4.2 MDa(eukaryotes) in size and undergo various conformational transitions during protein synthesis to translate the genetic code into the nascent polypeptide chains. Recent advances in cryo-electron microscopy (cryo-EM) and image processing methods have provided numerous detailed structures of rib...
Source: Progress in Biophysics and Molecular Biology - Category: Molecular Biology Source Type: research
(University of Maryland School of Medicine) Each year, millions of people contract serious diarrheal illnesses typically from contaminated food and water. Among the biggest causes of diarrheal diseases are the bacteria Shigella and enterotoxigenic Escherichia coli (ETEC), and researchers at the University of Maryland School of Medicine are testing a vaccine designed to offer protection against these serious pathogens.
Source: EurekAlert! - Infectious and Emerging Diseases - Category: Infectious Diseases Source Type: news
An oral, inactivated enterotoxigenic Escherichia coli (ETEC) vaccine (ETVAX) is safe and immunogenic in children, according to a new phase-1/2 trial.Reuters Health Information
Source: Medscape Allergy Headlines - Category: Allergy & Immunology Tags: Infectious Diseases News Source Type: news
Publication date: Available online 9 December 2019Source: Biochimica et Biophysica Acta (BBA) - BiomembranesAuthor(s): Jingjing Guo, Geraldine W.N. Chia, Nikolay V. Berezhnoy, Amaury Cazenave-Gassiot, Staffan Kjelleberg, Jamie Hinks, Yuguang Mu, Thomas SeviourAbstractThe outer membrane (OM) is the first defence for Gram-negative bacteria against their environments making it important in strain improvement for sustainable biobutanol production. While modifying the OM structure using chemical additives could enhance microbial viability, there are currently no model systems that accurately describe OM responses to butanol. He...
Source: Biochimica et Biophysica Acta (BBA) Biomembranes - Category: Biochemistry Source Type: research
Publication date: Available online 9 December 2019Source: PolymerAuthor(s): O.I. Timaeva, N.A. Arkharova, A.S. Orekhov, V.V. Klechkovskaya, S.P. Mulakov, G.M. Kuz'micheva, I.I. PashkinAbstractComposite hydrogels in the poly-N-vinylpyrrolidone – RE(NO3)3 × xH2O system with RE = La, Gd, Yb were prepared in various forms (native, native dried in the air, dried in air and ground into powder). They were studied by methods of wide- and small-angle X-ray scattering, differential scanning calorimetry, scanning electron microscopy, and electron microprobe analysis. The composition of native PVP and PVP with powd...
Source: Polymer - Category: Chemistry Source Type: research
ConclusionPatients with MC were more likely to have both hyperplastic polyp and LG adenoma. If confirmed, such findings could suggest the discontinuation of anthranoid laxative use particularly in the elderly.
Source: International Journal of Colorectal Disease - Category: Gastroenterology Source Type: research
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