Mass spectrometry-based glycoprofiling of biopharmaceuticals by using an automated data processing tool: SimGlycan®

The therapeutic and immunological properties of biopharmaceuticals are governed by the glycoforms contained in them. Thus, bioinformatics tools capable of performing comprehensive characterization of glycans are significantly important to the biopharma industry. The primary structural elucidation of glycans using mass spectrometry is tricky and tedious in terms of spectral interpretation. In this study, the biosimilars of a therapeutic monoclonal antibody and an Fc-fusion protein with moderate and heavy glycosylation, respectively, were employed as representative biopharmaceuticals for released glycan analysis using liquid chromatography–tandem mass spectrometry instead of conventional mass spectrometry-based analysis. SimGlycan® is a software with proven ability to process tandem MS data for released glycans could identify eight additional glycoforms in Fc-fusion protein biosimilar, which were not detected during mass spectrometry analysis of released glycans or glyco-peptide mapping of the same molecule. Thus, liquid chromatography–tandem mass spectrometry analysis of released glycans not only complements conventional liquid chromatography–mass spectrometry-based glycan profiling but can also identify additional glycan structures that may otherwise be omitted during conventional liquid chromatography–tandem mass spectrometry based analysis of mAbs. The mass spectrometry data processing tools, such as PMI Byos™, SimGlycan^®, etc., can display pivotal analytical capabilities in automated liquid chromatography–mass spectrometry and liquid chromatography–tandem mass spectrometry-based glycan analysis workflows, especially for high-throughput structural characterization of glycoforms in biopharmaceuticals.     

Intramolecular Diels–Alder reaction for the synthesis of tetracyclic carbazoles and isocanthines

One pot intramolecular Diels–Alder reaction has been efficiently used as a new route for the synthesis of four tetracyclic carbazoles and four isocanthine analogues where a dialdehyde is utilised as a common intermediate for both the scaffolds. Biological activity was evaluated for some molecules, which demonstrated moderate activity against HeLa cervical cancer cell lines.     

Combination of AlCl3, Ionic Liquid,and Microwaves: An Efficient Method for Dehydration and 1,3-Dipolar Cycloaddition: An Unusual Observation in the Presence of Acrylonitrile

Use of a combination of ionic liquids in the presence of aluminium chloride and microwave irradiation was shown to be a very efficient and high-yielding method for the dehydration of aldoximes and also for 1,3-dipolar cycloadditions. Surprisingly, the presence of acrylonitrile rendered an unusual formation of substituted amide.     

Indium(III) Chloride: An Efficient Catalyst for the Synthesis of Amidoalkyl Naphthols

Indium chloride was found to be a very efficient catalyst for the synthesis of amidoalkyl naphthols from β-naphthol, aromatic aldehydes, and acetamide/urea under solvent-free conditions using microwave irradiation.     

A versatile structural domain analysis server using profile weight matrices

The WEB tool "AnDom" assigns to a given protein sequence all experimentally determined structural domains contained within it, including multidomain and large proteins. The server uses profile specific matrices from custom generated multiple sequence alignments of all known SCOP domains (SCOP version 1.50). Prediction time is short allowing numerous applications for structural genomics including investigation of complex eucaryotic protein families. The WWW server is at http://www.bork.embl-heidelberg.de/AnDom, and profiles can be downloaded at ftp.bork.embl-heidelberg.de/pub/users/ schmidt/AnDom.     

Compressions of ta10w alloy kennertium w-2, and beryllium oxide to 4.5 GPa

Abstract

The volume compressions of a tantalum alloy, tungsten alloy, and beryllium oxide (BeO) have been derived from the measurements of axial shortenings of cylindrical specimens of these materials to 4.5 GPa at room temperature. These measurements were carried out in a solid pressure medium piston- cylinder apparatus.     

Simultaneous separation and identification of limonoids from citrus using liquid chromatography-collision-induced dissociation mass spectra

Limonoids are considered as potential cancer chemopreventive agents and are widely distributed in the Citrus genus as aglycones and glucosides. In the present study, reversed-phase HPLC coupled with CID mass spectra was developed for the simultaneous separation and identification of aglycones and glucosides of limonoids from citrus. Five aglycones such as limonin, deacetyl nomilin, ichangin, isolimonoic acid and nomilin were identified by positive ion CID MS/MS, whereas five glucosides, viz. limonin glucoside, isoobacunoic acid glucoside, obacunone glucoside, deacetyl nomilinic acid glucoside and nomilinic acid glucoside were analyzed by negative ion CID mass spectra. The developed method was successfully applied to complex citrus samples for the separation and identification of aglycones and glucosides. Citrus seeds were extracted with methanol and partially purified and analyzed by LC-CID mass spectra. The separation was achieved by C-18 column; eight limonoids were identified by comparing the retention times and mass spectral fragmentation. To the best of our knowledge, this is the first report on the identification of citrus limonoids using CID technique.     

One-pot solvothermal synthesis of FePt/Fe3O4 core-shell nanoparticles

Via a facile, one-pot solvothermal synthesis, highly uniform FePt/Fe3O4 core-shell nanoparticles are successfully developed, which further demonstrates their superiority in the MR imaging of living cells.     

Radiation inactivation study of aminopeptidase: probing the active site

Ionizing radiation inactivated purified chicken intestinal aminopeptidase in media saturated with gases in the order N₂O>N₂>air. The D₃₇ values in the above conditions were 281, 210 and 198 Gy, respectively. OH radical scavengers such as t-butanol and isopropanol effectively nullified the radiation-induced damage in N₂O. The radicals (SCN)₂^•−, Br₂^•− and I₂^•− inactivated the enzyme, pointing to the involvement of aromatic amino acids and cysteine in its catalytic activity. The enzyme exhibited fluorescence emission at 340 nm which is characteristic of tryptophan. The radiation-induced loss of activity was accompanied by a decrease in the fluorescence of the enzyme suggesting a predominant influence on tryptophan residues. The enzyme inhibition was associated with a marked increase in the K_m and a decrease in the V_max and k_cat values, suggesting an irreversible alteration in the catalytic site. The above observations were confirmed by pulse radiolysis studies.     

In Silico Studies Reveal Peramivir and Zanamivir as an Optimal Drug Treatment Even If H7N9 Avian Type Influenza Virus Acquires Further Resistance

An epidemic of avian type H7N9 influenza virus, which took place in China in 2013, was enhanced by a naturally occurring R294K mutation resistant against Oseltamivir at the catalytic site of the neuraminidase. To cope with such drug-resistant neuraminidase mutations, we applied the molecular docking technique to evaluate the fitness of the available drugs such as Oseltamivir, Zanamivir, Peramivir, Laninamivir, L-Arginine and Benserazide hydrochloride concerning the N9 enzyme with single (R294K, R119K, R372K), double (R119_294K, R119_372K, R294_372K) and triple (R119_294_372K) mutations in the pocket. We found that the drugs Peramivir and Zanamivir score best amongst the studied compounds, demonstrating their high binding potential towards the pockets with the considered mutations. Despite the fact that mutations changed the shape of the pocket and reduced the binding strength for all drugs, Peramivir was the only drug that formed interactions with the key residues at positions 119, 294 and 372 in the pocket of the triple N9 mutant, while Zanamivir demonstrated the lowest RMSD value (0.7 Å) with respect to the reference structure.