Read by QxMD icon Read


Valentin Al Jalali, Markus Zeitlinger
Telavancin was discovered by modifying the chemical structure of vancomycin and belongs to the group of lipoglycopeptides. It employs its antimicrobial potential through two distinct mechanisms of action: inhibition of bacterial cell wall synthesis and induction of bacterial membrane depolarization and permeabilization. In this article we review the clinically relevant pharmacokinetic and pharmacodynamic data of telavancin. For comparison, the pharmacokinetic and pharmacodynamic data of the other glycopeptides are presented...
January 13, 2018: Clinical Pharmacokinetics
Ye' Zaw Phyo, Sara Cravo, Andreia Palmeira, Maria Elizabeth Tiritan, Anake Kijjoa, Madalena M M Pinto, Carla Fernandes
A systematic study of enantioresolution of a library of xanthonic derivatives, prepared "in-house", was successfully carried out with four commercially available macrocyclic glycopeptide-based columns, namely ChirobioticTM T, ChirobioticTM R, ChirobioticTM V and ChirobioticTM TAG. Evaluation was conducted in multimodal elution conditions: normal-phase, polar organic, polar ionic and reversed-phase. The effects of the mobile phase composition, the percentage of organic modifier, the pH of the mobile phase, the nature and concentration of different mobile phase additives on the chromatographic parameters are discussed...
January 11, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Li Qun Xu, Yan Biao Liao, Ning Ning Li, Yi Jian Li, Jie Yu Zhang, Yun Bing Wang, Xue Feng Hu, Chang Ming Li
Chemical reduction of graphene oxide (GO) is a simple and inexpensive method for the large-scale production of graphene-based materials. A suitable reducing agent, especially a green reductant, is in high demand for the production of reduced GO (RGO). Vancomycin, a glycopeptide antibiotic used to treat a variety of Gram-positive bacterial infections, was used to chemically reduce GO at a weak alkaline pH. As far as we know, this is the first report of reduction of GO by a glycopeptide antibiotic. The resulting vancomycin-decorated RGO (RGO-Van) was characterized by UV-visible adsorption and Raman spectroscopies, X-ray diffraction pattern and atomic force microscopy (AFM)...
January 4, 2018: Journal of Colloid and Interface Science
Hironobu Hojo, Yuya Asahina, Naoki Takeda, Toshiki Takei
Amino acids carrying 4-methylbenzyl (MBn) and 4-methoxybenzyl (MPM)-protected sialic acid were synthesized and used for the 9-fluorenylmethoxycarbonyl (Fmoc) solid-phase synthesis of a glycopeptide. The alpha-sialyl linkage of the MBn-protected unit was partially cleaved under the final deprotection by trifluoroacetic acid (TFA). In addition, the removal of several MBn groups were incomplete. On the other hand, the MPM-protected unit gave the desired glycopeptide without decomposition of the -sialyl linkage...
January 3, 2018: Chemistry: a European Journal
Xiaoyan Feng, Chunhui Deng, Mingxia Gao, Guoquan Yan, Xiangmin Zhang
High-efficient enrichment of glycopeptides prior to mass spectrometry is essential for glycoproteomics analysis. Hydrophilic interaction chromatography (HILIC) approach is a prominent strategy for glycopeptides identification. In this work, glucose functionalized magnetic graphene hydrophilic nanocomposite (MagG/Au/Glu) was synthesized as a novel HILIC material via a facile surface modification strategy. Different from previous click synthesis of saccharides-functionalized materials, glucose was easily thiolated via Traut's reagent and then immobilized on the materials via efficient Au-S coupling, greatly simplifying the synthesis process...
March 1, 2018: Talanta
Yanyan Qu, Liangliang Sun, Guijie Zhu, Zhenbin Zhang, Elizabeth H Peuchen, Norman J Dovichi
Glycoproteomic analysis requires efficient separation and sensitive detection to enable the comprehensive characterization of glycan heterogeneity. Here, we report the use of capillary zone electrophoresis-electrospray ionization-mass spectrometry (CZE-ESI-MS) with an electrokinetically-pumped nanospray interface for the study of protein glycosylation microheterogeneity. A fast separation was developed that resolved intact glycopeptides generated from standard proteins within ~9min. Differentially terminal-galactosylated and sialylated species with the same glycosylation sites were well resolved...
March 1, 2018: Talanta
J W Betts, H F Abdul Momin, L M Phee, D W Wareham
PURPOSE: Glycopeptides are widely used for the treatment of meticillin-resistant Staphylococcus aureus (MRSA) infections. Although difficult to detect, isolates with reduced (GISA), hetero (hGISA) or complete (GRSA) resistance to glycopeptides are increasingly reported. Optimal therapy for such strains is unknown. We compared the in vitro and in vivo activity of tedizolid (TED), a recently licensed oxazolidonone, with vancomycin (VAN) and teicoplanin (TEIC) combined with fusidic acid (FD) or rifampicin (RIF) against S...
January 4, 2018: Journal of Medical Microbiology
Kanne Padmaja, Sukanya Sudhaharan, Lakshmi Vemu, Oruganti Sai Satish, Padmasri Chavali, Mamidi Neeraja
Background and Objectives: Infective endocarditis (IE) is a microbial infection of the endothelial surface of the cardiac-valves. Rapid diagnosis, effective treatment and prompt recognition of complications are essential, in order to improve the outcome. We retrospectively reviewed and determined the clinical characteristics, microbiological profile and management strategies of IE cases, changing microbial spectrum of pathogens and outcome in Native Valve Endocarditis (NVE) and Prosthetic Valve Endocarditis (PVE) cases...
October 2017: Iranian Journal of Microbiology
Mark A T Blaskovich, Karl A Hansford, Yujing Gong, Mark S Butler, Craig Muldoon, Johnny X Huang, Soumya Ramu, Alberto B Silva, Mu Cheng, Angela M Kavanagh, Zyta Ziora, Rajaratnam Premraj, Fredrik Lindahl, Tanya A Bradford, June C Lee, Tomislav Karoli, Ruby Pelingon, David J Edwards, Maite Amado, Alysha G Elliott, Wanida Phetsang, Noor Huda Daud, Johan E Deecke, Hanna E Sidjabat, Sefetogi Ramaologa, Johannes Zuegg, Jason R Betley, Andrew P G Beevers, Richard A G Smith, Jason A Roberts, David L Paterson, Matthew A Cooper
The public health threat posed by a looming 'post-antibiotic' era necessitates new approaches to antibiotic discovery. Drug development has typically avoided exploitation of membrane-binding properties, in contrast to nature's control of biological pathways via modulation of membrane-associated proteins and membrane lipid composition. Here, we describe the rejuvenation of the glycopeptide antibiotic vancomycin via selective targeting of bacterial membranes. Peptide libraries based on positively charged electrostatic effector sequences are ligated to N-terminal lipophilic membrane-insertive elements and then conjugated to vancomycin...
January 2, 2018: Nature Communications
Jua Lee, Serenus Hua, Sung Hyeon Lee, Myung Jin Oh, Jaekyung Yun, Jin Young Kim, Jae-Han Kim, Jung Hoe Kim, Hyun Joo An
Gastric cancer (GC) is one of the leading causes of cancer-related death worldwide, largely because of difficulties in early diagnosis. Despite accumulating evidence indicating that aberrant glycosylation is associated with GC, site-specific localization of the glycosylation to increase specificity and sensitivity for clinical use is still an analytical challenge. Here, we created an analytical platform with a targeted glycoproteomic approach for GC biomarker discovery. Unlike the conventional glycomic approach with untargeted mass spectrometric profiling of released glycan, our platform is characterized by three key features: it is a target-protein-specific, glycosylation-site-specific, and structure-specific platform with a one-shot enzyme reaction...
December 29, 2017: Analytical and Bioanalytical Chemistry
Alessia Savoldi, Anna M Azzini, David Baur, Evelina Tacconelli
PURPOSE OF REVIEW: Skin and soft-tissue infections (SSIs) are among the commonest infections encountered in clinical practice. Spread of methicillin-resistant Staphylococcus aureus SSIs continues to increase in both health care and community settings and presents a challenge for the best treatment choice. Vancomycin has been the mainstay of SSIs treatment, but recently its use has been questioned because of concerns about its efficacy, tolerability, and unfavorable pharmacokinetic/pharmacodynamic profile...
December 27, 2017: Current Opinion in Infectious Diseases
Heajin Park, Jihye Kim, Young Kwang Lee, Wooseok Kim, Seung Kwan You, Jonghye Do, Yeonjoo Jang, Doo-Byung Oh, Jae Il Kim, Ha Hyung Kim
Myozyme is a recombinant human acid alpha-glucosidase (rhGAA) that is currently the only drug approved for treating Pompe disease, and its low efficacy means that a high dose is required. Mannose-6-phosphate (M6P) glycosylation on rhGAA is a key factor influencing lysosomal enzyme targeting and the efficacy of enzyme replacement therapy (ERT); however, its complex structure and relatively small quantity still remain to be characterized. This study investigated M6P glycosylation on rhGAA using liquid chromatography (LC)-electrospray ionization (ESI)-high-energy collisional dissociation (HCD) tandem mass spectrometry (MS/MS)...
December 20, 2017: Biochemical and Biophysical Research Communications
Mercedes Verdugo-Perales, Rosabel Velez-de la Rocha, Josefina León-Félix, Tomas Osuna-Enciso, José B Heredia, Juan A Osuna-Castro, Maria A Islas-Osuna, J Adriana Sañudo-Barajas
Lysine-rich (Lys-rich) proteins encoded by AGP17, AGP18, and AGP19 genes are cell wall-associated glycopeptides related to sexual reproduction in flowering plants. This subclass belongs to classical arabinogalactan proteins (AGPs) widely studied in model plants like Arabidopsis. In this study, we identified the CaAGP18 cDNA from bell pepper (Capsicum annuum L.), as well as its expression pattern during vegetative and reproductive development. The deduced amino acid sequence revealed a Lys-rich AGP18 protein of 238 amino acids residues in length with an estimated molecular mass of 22...
January 2018: 3 Biotech
Melanie Roch, Paula Gagetti, James Davis, Paola Ceriana, Laura Errecalde, Alejandra Corso, Adriana E Rosato
Daptomycin remains as one of the main treatment options for Methicillin-Resistant Staphylococcus aureus (MRSA). Sporadic resistance cases reported in patients treated with either daptomycin or glycopeptides are a growing concern. In a previous study, we described a clinical case of a patient with a community-acquired MRSA infection resistant to daptomycin and with intermediate resistance to vancomycin who developed a recurrent infection with a susceptible isogenic strain. In the present work, we further investigated the sequential events to determine whether the switch from a daptomycin resistance to a susceptible phenotype was due to a phenomenon of resistance reversion or recurrent infection with a susceptible strain...
2017: Frontiers in Microbiology
Vladimir Vimberg, Jorunn Pauline Cavanagh, Oldřich Benada, Olga Kofroňová, Erik Hjerde, Leona Zieglerová, Gabriela Balíková Novotná
We investigated the genetic basis of glycopeptide resistance in laboratory-derived strains of S. haemolyticus with emphasis on differences between vancomycin and teicoplanin. The genomes of two stable teicoplanin-resistant laboratory mutants selected on vancomycin or teicoplanin were sequenced and compared to parental S. haemolyticus strain W2/124. Only the two non-synonymous mutations, VraS Q289K and WalK V550L were identified. No other mutations or genome rearrangements were detected. Increased cell wall thickness, resistance to lysostaphin-induced lysis and adaptation of cell growth rates specifically to teicoplanin were phenotypes observed in a sequenced strain with the VraS Q289K mutation...
November 16, 2017: Diagnostic Microbiology and Infectious Disease
Wei Zeng, Kristina L Ford, Tony Bacic, Joshua L Heazlewood
N-glycosylation is one of the most common protein post-translational modifications in eukaryotes and has a relatively conserved core structure between fungi, animals and plants. In plants, the biosynthesis of N-glycans has been extensively studied with all the major biosynthetic enzymes characterized. However, few studies have applied advanced mass spectrometry to profile intact plant N-glycopeptides. In this study, we use hydrophilic enrichment, high-resolution tandem mass spectrometry with complementary and triggered fragmentation to profile Arabidopsis N-glycopeptides from microsomal membranes of aerial tissues...
December 13, 2017: Molecular & Cellular Proteomics: MCP
Shibu Krishnan, Harry J Whitwell, Joy Cuenco, Aleksandra Gentry-Maharaj, Usha Menon, Stephen P Pereira, Marco Gaspari, John F Timms
Biomarkers for the early detection of pancreatic cancer are urgently needed. The aim of this pilot study was to evaluate changes in serum N-glycoproteins and their glycosylation status prior to clinical presentation of pancreatic cancer that may be potential biomarkers. Prediagnosis serum samples pooled according to five time-to-diagnosis groups and a non-cancer control pool were digested with trypsin, labelled with mass tags, and subjected to titanium dioxide capture, deglycosylation, and 2D-LC-MS/MS profiling...
December 9, 2017: International Journal of Molecular Sciences
Yanyan Qu, Liangliang Sun, Zhenbin Zhang, Norman J Dovichi
Reversed-phase chromatographic separation of glycopeptides tends to be dominated by the peptide composition. In contrast, capillary zone electrophoresis separation of glycopeptides is particularly sensitive to the sialic acid composition of the glycan. In this paper, we combine the two techniques to achieve superior N-glycopeptide analysis. Glycopeptides were first isolated from a tryptic digest using HILIC solid-phase extraction. The glycopeptides were separated using reversed-phase UHPLC to generate four fractions corresponding to different peptide backbones...
December 12, 2017: Analytical Chemistry
Qiwei Zhang, Zack Li, Yawei Wang, Qi Zheng, Jianjun Li
Sialic acids are a family of structurally unique and negatively charged nine-carbon sugars, normally found at the terminal positions of glycan chains on glycoproteins and glycolipids. The glycosylation of proteins is a universal post-translational modification in eukaryotic species and regulates essential biological functions, in which the most common sialic acid is N-acetyl-neuraminic acid (2-keto-5-acetamido-3,5-dideoxy-D-glycero-D-galactononulopyranos-1-onic acid) (Neu5NAc). Because of the properties of sialic acids under general mass spectrometry (MS) conditions, such as instability, ionization discrimination, and mixed adducts, the use of MS in the analysis of protein sialoglycosylation is still challenging...
December 11, 2017: Mass Spectrometry Reviews
Ting Song, Peng Chen, Carol Stroble, L Renee Ruhaak, Haibin Wang, Ziqi Li, Wei He, Carlito B Lebrilla
Osteonecrosis of the femoral head is a recalcitrant and paralyzing disease often discovered in the end stage at the time of diagnosis, which is often performed by physical examination and diagnostic imaging. Osteonecrosis of the femoral head is typically caused by trauma or long-term steroid use. There are over 30 million patients in the US taking steroids, and roughly 40% will develop osteonecrosis of the femoral head. However, the exact pathophysiological process is not well understood. This study aims to examine the alteration in serum glycosylation of osteonecrosis of the femoral head using the state-of-the-art analytical tools to provide more chemical data for pathophysiology research and possibly biomarker discovery...
January 1, 2017: European Journal of Mass Spectrometry
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"