Read by QxMD icon Read


Mustafa Nakipoğlu, Fadime Yilmaz, Bulent Icgen
Untreated wastewaters and treated effluents even after final disinfection contain antibiotic resistant bacteria and resistance genes before they are released into surface waters. A correlation between resistant bacteria and antibiotics in surface waters has been found, as have antibiotic resistance genes. Of particular interest are vancomycin-resistant enterococci harboring vanA gene that confers high level of resistance to glycopeptide antibiotics including teicoplanin. Therefore, in this study, river water samples were analysed to investigate vancomycin- and teicoplanin-resistant bacterial isolates harboring vanA gene...
October 21, 2016: Bulletin of Environmental Contamination and Toxicology
Dongping Yu, Zhimou Guo, Aijin Shen, Jingyu Yan, Xuefang Dong, Gaowa Jin, Zhen Long, Lina Liang, Xinmiao Liang
Zwitterionic polymer stationary phases have attracted increasing attention in hydrophilic interaction chromatography (HILIC). In this work, a zwitterionic sulfobetaine functionalized polyacrylamide stationary phase (named TENS) based on porous silica particles was prepared via controlled surface initiated reversible addition-fragmentation transfer (RAFT) polymerization. Instead of traditional methacrylate type sulfobetaine monomer, acrylamide type sulfobetaine monomer, which has higher chemical stability and hydrophicility, was employed in this work...
December 1, 2016: Talanta
Aisha Bibi, Huangxian Ju
This work presents an efficient and selective enrichment method for glycoprotein/glycopeptides with sulfonic acid-functionalized mesoporous silica (SBA-15-SO3H), which is synthesized via simple oxidation of -SH groups with H2O2. The functionalized SBA-15 shows large surface area and accessible pores, and can selectively adsorb glycopeptides via hydrogen bond and hydrophilic interaction. Upon the selective enrichment prior to the mass spectrometric (MS) analysis, the signals of glycopeptides are significantly enhanced, which leads to the identifiable signals of 21 glycopeptides from the digest of HRP, 16 glycopeptides from the digest of human IgG, and 16 glycopeptides from the digest of chicken avidin...
December 1, 2016: Talanta
Pierre Dehoux, Jean Christophe Marvaud, Amr Abouelleil, Ashlee M Earl, Thierry Lambert, Catherine Dauga
BACKGROUND: Clostridium bolteae and Clostridium clostridioforme, previously included in the complex C. clostridioforme in the group Clostridium XIVa, remain difficult to distinguish by phenotypic methods. These bacteria, prevailing in the human intestinal microbiota, are opportunistic pathogens with various drug susceptibility patterns. In order to better characterize the two species and to obtain information on their antibiotic resistance genes, we analyzed the genomes of six strains of C...
October 21, 2016: BMC Genomics
Adam Pap, Katalin F Medzihradszky, Zsuzsanna Darula
Growing evidence on the diverse biological roles of extracellular glycosylation as well as the need for quality control of protein pharmaceuticals make glycopeptide analysis both exciting and important again after a long hiatus. High-throughput O-glycosylation studies have to tackle the complexity of glycosylation as well as technical difficulties and, up to now, have yielded only limited results mostly from single enrichment experiments. In this study, we address the technical reproducibility of the characterization of the most prevalent O-glycosylation (mucin-type core 1 structures) in human serum, using a two-step lectin affinity-based workflow...
October 20, 2016: Analytical and Bioanalytical Chemistry
Salvatore Fanali
This paper presents the state of the art concerning the separation of chiral compounds by means of nano-liquid chromatography (nano-LC). The enantiomers' separation and determination are a subject of fundamental importance in various application fields such as pharmaceutical industry, biomedicine, food, agrochemical etc. Nano-LC is a miniaturized chromatographic technique offering some advantages over conventional ones such as low consumption of mobile phase, sample volume and amount of chiral stationary phase, reduced costs etc...
October 14, 2016: Journal of Chromatography. A
Ju Yeon Lee, Hyun Kyoung Lee, Gun Wook Park, Heeyoun Hwang, Hoi Keun Jeong, Ki Na Yun, Eun Sun Ji, Kwang Hoe Kim, Jun Seok Kim, Jong Won Kim, Sung Ho Yun, Chi-Won Choi, Seung Il Kim, Jong-Sun Lim, Seul-Ki Jeong, Young-Ki Paik, Soo-Youn Lee, Jisook Park, Su Yeon Kim, Young-Jin Choi, Yong-In Kim, Jawon Seo, Je-Yoel Cho, Myoung Jin Oh, Nari Seo, Hyun Joo An, Jin Young Kim, Jong Shin Yoo
Glycoprotein conformations are complex and heterogeneous. Currently, site-specific characterization of glycopeptides is a challenge. Herein, we sought to establish an efficient method of N-glycoprotein characterization using mass spectrometry. Using alpha-1-acid glycoprotein (AGP) as a model N-glycoprotein, its tryptic N-glycopeptides were identified, and the reproducibility of the data was examined in seven laboratories running different liquid chromatography-mass tandem spectrometry (LC-MS/MS) platforms. We used three test samples and one blind sample to evaluate instrument performance with entire sample preparation workflow...
October 19, 2016: Journal of Proteome Research
Nathan J Hare, Ling Y Lee, Ian Loke, Warwick J Britton, Bernadette M Saunders, Morten Thaysen-Andersen
Tuberculosis (TB) remains a prevalent and lethal infectious disease. The glycobiology associated with Mycobacterium tuberculosis infection of front-line alveolar macrophages is still unresolved. Herein, we investigated the regulation of protein N-glycosylation in human macrophages and their secreted microparticles (MPs) used for intercellular communication upon M. tb infection. LC-MS/MS-based proteomics and glycomics were performed to monitor the regulation of glycosylation enzymes and receptors and the N-glycome in in vitro-differentiated macrophages and in isolated MPs upon M...
October 19, 2016: Journal of Proteome Research
Grace Yim, Wenliang Wang, Maulik N Thaker, Stephanie Tan, Gerard D Wright
Modification of natural product backbones is a proven strategy for the development of clinically useful antibiotics. Such modifications have traditionally been achieved through medicinal chemistry strategies or via in vitro enzymatic activities. In an orthogonal approach, engineering of biosynthetic pathways using synthetic biology techniques can generate chemical diversity. Here we report the use of a minimal teicoplanin class glycopeptide antibiotic (GPA) scaffold expressed in a production-optimized Streptomyces coelicolor strain to expand GPA chemical diversity...
September 9, 2016: ACS Infectious Diseases
Laura Bouché, Maria Panico, Paul Hitchen, Daniel Binet, Federico Sastre, Alexandra Faulds-Pain, Esmeralda Valiente, Evgeny Vinogradov, Annie Aubry, Kelly Fulton, Susan Twine, Susan M Logan, Brendan W Wren, Anne Dell, Howard R Morris
Glycosylation of flagellins is a well recognized property of many bacterial species. In this study we describe the structural characterization of novel flagellar glycans from a number of hypervirulent strains of C. difficile. We used mass spectrometry (nano LC- MS and MS/MS analysis) to identify a number of putative glycopeptides which carried a variety of glycoform substitutions each of which was linked through an initial HexNAc residue to Ser or Thr. Detailed analysis of a LLDGSSTEIR glycopeptide released by tryptic digestion, which carried two variant structures, revealed that the glycopeptide contained, in addition to carbohydrate moieties, a novel structural entity...
October 7, 2016: Journal of Biological Chemistry
Leena Liljedahl, Maiken Højgaard Pedersen, Jenny Norlin, James N McGuire, Peter James
BACKGROUND: Diabetic nephropathy (DN) is a late complication in both type 1 diabetes mellitus (T1DM) and T2DM. Already at an early stage of DN morphological changes occur at the cell surface and in the extracellular matrix where the majority of the proteins carry N-linked glycosylations. These glycosylated proteins are highly important in cell adhesion and cell-matrix processes but not much is known about how they change in DN or whether the distinct etiology of T1DM and T2DM could have an effect on their abundances...
2016: Clinical Proteomics
Madeleine Peschke, Clara Brieke, Max J Cryle
The glycopeptide antibiotics are peptide-based natural products with impressive antibiotic function that derives from their unique three-dimensional structure. Biosynthesis of the glycopeptide antibiotics centres of the combination of peptide synthesis, mediated by a non-ribosomal peptide synthetase, and the crosslinking of aromatic side chains of the peptide, mediated by the action of a cascade of Cytochrome P450s. Here, we report the first example of in vitro activity of OxyE, which catalyses the F-O-G ring formation reaction in teicoplanin biosynthesis...
October 18, 2016: Scientific Reports
Emily S Starn, Holly Hampe, Thomas Cline
Health care facility-acquired Clostridium difficile infections (HCFA-CDI) have increased over the last several decades despite facilities developing protocols for prescribing probiotics with antibiotics to prevent HCFA-CDI. The literature does not consistently support this. A retrospective medical record review evaluated the care effectiveness of this practice. Care effectiveness was not found; patients receiving probiotics with antibiotics were twice as likely to develop HCFA-CDI (P = .004). Except with glycopeptides, patients were 1...
October 2016: Quality Management in Health Care
Alba Hykollari, Katharina Paschinger, Barbara Eckmair, Iain B H Wilson
N-glycans from invertebrates and protists have often unusual structures which present analytical challenges. Both core and antennal modifications can be quite different from the more familiar vertebrate glycan motifs; thereby, contrary to the concept that "simple" organisms have "simple" N-glycans, rather complex oligosaccharides structures, including zwitterionic and anionic ones, have been found in a range of species. Thus, to facilitate the optimized elucidation of the maximal possible range of structures, the analytical workflow for glycomics of these organisms should include sequential release and fractionation steps...
2017: Methods in Molecular Biology
Kathrin Stavenhagen, Hannes Hinneburg, Daniel Kolarich, Manfred Wuhrer
The vast heterogeneity of protein glycosylation, even of a single glycoprotein with only one glycosylation site, can give rise to a set of macromolecules with different physicochemical properties. Thus, the use of orthogonal approaches for comprehensive characterization of glycoproteins is a key requirement. This chapter describes a universal workflow for site-specific N- and O-glycopeptide analysis. In a first step glycoproteins are treated with Pronase to generate glycopeptides containing small peptide sequences for enhanced glycosylation site assignment and characterization...
2017: Methods in Molecular Biology
L Renee Ruhaak
In recent years, high-throughput glycomics approaches have been developed and applied to either complete biofluids, cell lysates or tissues, or proteins isolated thereof. However, during such analyses the N-glycan are released from the protein backbone and therefore site- and protein-specific information is lost. There exists a need for high-throughput methods that allow quantification of site- and protein-specific glycosylation patterns from complex biological mixtures. We here describe the use of a multiple reaction monitoring mass spectrometry based method for the generation of glycopeptide profiles of the nine high abundance glycoproteins IgG, IgA, IgM, haptoglobin, alpha-1-antitrypsin, alpha-2-macroglobulin, alpha-1-acid glycoprotein, transferrin, and complement C3...
2017: Methods in Molecular Biology
Noortje de Haan, Karli R Reiding, Manfred Wuhrer
Matrix-assisted laser desorption/ionization (MALDI)-time-of-flight (TOF)-mass spectrometry (MS) is a highly suitable method for the rapid analysis of IgG glycopeptides, providing a wealth of structural information. A limitation of this approach is that it generates a bias when analyzing sialylated species due to the labile nature of sialic acid glycosidic linkages. One way to overcome this problem is by chemical derivatization of the sialic acids. The method presented here results in both the stabilization of the sialic acids, as well as the differentiation of α2,3- and α2,6-linked sialic acids by mass...
2017: Methods in Molecular Biology
David Falck, Bas C Jansen, Noortje de Haan, Manfred Wuhrer
This chapter contains a nanoscale liquid chromatography-mass spectrometry method for the glycoform profiling of the conserved Fc N-glycosylation site of monoclonal and polyclonal immunoglobulin G (IgG). It describes in detail LaCyTools, a program for automated data (pre-)processing of the obtained LC-MS data. The minimal sample preparation necessary is explained as well as an optional method for affinity purification of (polyclonal) antibodies from serum or plasma.After (optional) affinity purification, the pure IgG is cleaved with trypsin...
2017: Methods in Molecular Biology
Kshitij Khatri, Joshua A Klein, Joseph Zaia
In order to interpret glycopeptide tandem mass spectra, it is necessary to estimate the theoretical glycan compositions and peptide sequences, known as the search space. The simplest way to do this is to build a naïve search space from sets of glycan compositions from public databases and to assume that the target glycoprotein is pure. Often, however, purified glycoproteins contain co-purified glycoprotein contaminants that have the potential to confound assignment of tandem mass spectra based on naïve assumptions...
October 12, 2016: Analytical and Bioanalytical Chemistry
Abiola Olumuyiwa Olaitan, Jean-Marc Rolain
Antibiotic resistance is an ancient biological mechanism in bacteria, although its proliferation in our contemporary world has been amplified through antimicrobial therapy. Recent studies conducted on ancient environmental and human samples have uncovered numerous antibiotic-resistant bacteria and resistance genes. The resistance genes that have been reported from the analysis of ancient bacterial DNA include genes coding for several classes of antibiotics, such as glycopeptides, β-lactams, tetracyclines, and macrolides...
August 2016: Microbiology Spectrum
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"