A5101817520- Metabolomics and Mass Spectrometry Studies
- Mass Spectrometry Techniques and Applications
- Analytical Chemistry and Chromatography
- Microbial Natural Products and Biosynthesis
- Fungal Biology and Applications
- Water Treatment and Disinfection
- Synthesis and bioactivity of alkaloids
- Protein Kinase Regulation and GTPase Signaling
- Environmental Chemistry and Analysis
- X-ray Diffraction in Crystallography
- Advanced Proteomics Techniques and Applications
- Lipid metabolism and biosynthesis
- Crystallization and Solubility Studies
- Plant biochemistry and biosynthesis
- Radioactive element chemistry and processing
- Electrochemical sensors and biosensors
- Infectious Diseases and Mycology
- Endoplasmic Reticulum Stress and Disease
- Protein Tyrosine Phosphatases
- Enzyme Structure and Function
- Virus-based gene therapy research
- Microbial infections and disease research
- Analytical Chemistry and Sensors
- Chemical Analysis and Environmental Impact
- Microbial Community Ecology and Physiology
Sookmyung Women's University
2020-2024
Biocrates Life Sciences (Austria)
2024
Tulane University
2024
University of Arkansas at Fayetteville
2019-2024
St Vincent's Hospital
2018
University of Wollongong
2009-2016
University of California, Riverside
2014-2016
Riverside
2016
Charité - Universitätsmedizin Berlin
2005
Technische Universität Berlin
2005
The complete structural elucidation of complex lipids, including glycerophospholipids, using only mass spectrometry represents a major challenge to contemporary analytical technologies. Here, we demonstrate that product ions arising from the collision-induced dissociation (CID) [M + Na](+) adduct phospholipids can be isolated and subjected subsequent gas-phase ozonolysis - known as ozone-induced (OzID) in linear ion-trap spectrometer. resulting CID/OzID experiment yields abundant are...
Ozone-induced dissociation (OzID) exploits the gas-phase reaction between mass-selected lipid ions and ozone vapor to determine position(s) of unsaturation. In this contribution, we describe modification a tandem linear ion-trap mass spectrometer specifically for OzID analyses wherein is supplied collision cell. This instrumental configuration provides spatial separation mass-selection, ozonolysis reaction, mass-analysis steps in process thus delivers significant enhancements speed...
In drinking water chloramination, monochloramine autodecomposition occurs in the presence of excess free ammonia through dichloramine, decay which was implicated N-nitrosodimethylamine (NDMA) formation by (i) dichloramine hydrolysis to nitroxyl reacts with itself nitrous oxide (N2O), (ii) reaction dissolved oxygen (DO) peroxynitrite or mono/dichloramine nitrogen gas (N2), and (iii) total dimethylamine (TOTDMA) NDMA decomposition nitrite/nitrate. Here, yields oxygen-containing end-products...
Hassallidin A (1), a new antifungal glycosylated lipopeptide, was isolated from an epilithic cyanobacterium collected in Bellano, Italy, identified as Tolypothrix (basionym Hassallia) species. Chemical, mass spectrometric, and spectroscopic analyses, including one- two-dimensional NMR, were performed to determine esterified eight-residue cyclic peptide linked with carbohydrate fatty acid residue. Chiral GC-MS analysis revealed the occurrence of nonproteinogenic amino acids d-allo-Thr, d-Thr,...
Ozone-induced dissociation (OzID) is an alternative ion activation method that relies on the gas phase ion-molecule reaction between a mass-selected target and ozone in trap mass spectrometer. Herein, we evaluated performance of OzID for both structural elucidation selective detection conjugated carbon-carbon double bond motifs within lipids. The relative reactivity trends [M + X]+ ions (where X = Li, Na, K) formed via electrospray ionization (ESI) versus nonconjugated fatty acid methyl...
Protein phosphatase 2A (PP2A) is very versatile owing to a large number of regulatory subunits and its ability interact with numerous other proteins. The A subunit exists as two closely related isoforms designated Aα Aβ. Mutations have been found in both variety human cancers. Although has intensely studied, little known about We generated Aβ-specific antibodies determined the cell cycle expression, subcellular distribution, metabolic stability Aβ comparison Aα. Both forms were expressed at...
The four transmembrane chemoreceptors of Escherichia coli sense phenol as either an attractant (Tar) or a repellent (Tap, Trg, and Tsr). In this study, we investigated the Tar determinants that mediate its response to Tsr phenol. molecules with lesions in aspartate-binding pocket periplasmic domain, foreign domain (from from several Pseudomonas chemoreceptors), lacking nearly entire still mediated responses Similarly, cytoplasmic methylation kinase control domains sensed attractant....
The N-nitrosodimethylamine (NDMA) formation pathway in chloraminated drinking water remains unresolved. In pH 7-10 waters amended with 10 μM total dimethylamine and 800 μeq Cl2·L-1 dichloramine (NHCl2), NDMA, nitrous oxide (N2O), dissolved oxygen (DO), NHCl2, monochloramine (NH2Cl) were kinetically quantified. N2O, DO profiles indicated that reactive nitrogen species (RNS) formed during NHCl2 decomposition, including nitroxyl/nitroxyl anion (HNO/NO-) peroxynitrous acid/peroxynitrite...
Glycosphingolipids (GSLs) are important metabolic regulators that control critical cellular functions and found in all cell membranes. GSL epimers which only differ the orientation of a single OH group indicators for different lysosomal storage diseases. In this study, we investigate structural discrimination isomers using radical-directed dissociation (RDD). Radical fragmentation species can be enabled by either noncovalent or covalent modification strategies. The results reveal RDD...
Phosphatidylethanolamines (PE) and phosphatidylcholines (PC) are important phospholipids frequently present in many types of cells. In some cases, PE has been equated with PC because they chemically very similar often isomeric species. this study, we demonstrate that noncovalent complexation between 18-crown-6 ether (18C6) can be used to quantitatively mass shift separate from phospholipids. Detection is also more sensitive by approximately an order magnitude addition 18C6. This approach...
Metabolomics and lipidomics are pivotal in understanding phenotypic variations beyond genomics. However, quantification comparability of mass spectrometry (MS)-derived data challenging. Standardised assays can enhance comparability, enabling applications multi-center epidemiological clinical studies. Here we evaluated the performance reproducibility MxP® Quant 500 kit across 14 laboratories. The allows 634 different metabolites from 26 compound classes using triple quadrupole MS. Each...
Biological species collections are critical for natural product drug discovery programs. However, prioritization of target in massive remains difficult. Here, we introduce an untargeted metabolomics-based workflow that uses MS/MS molecular networking to estimate scaffold-level distribution. As a demonstration, applied the 40 polyporoid fungal species. Nine were prioritized as candidates based on chemical structural and compositional similarity (CSCS) metric. Most selected showed relatively...
Background: Endolichenic fungi (ELF), which live the inside lichen thallus, contain many secondary metabolites that show various biological activities. Recent studies and ELF have antioxidant, antibacterial, antifungal, cytotoxic, anticancer Purpose: Here, effects of an extract its bioactive compounds were investigated on H1975 cell line focusing immune checkpoint marker inhibition. Methods: An was isolated from host Bryoria fuscescens (Gyelnik) Brodo D. Hawksw identified species as Nemania...
The protein phosphatase 2A holoenzyme is composed of one catalytic C subunit, regulatory/scaffolding A and regulatory B subunit. core enzyme consists subunits only. both exist as two closely related isoforms, alpha beta. belong to four weakly or unrelated families, designated B, B', B", B"', with multiple members in each family. existence subunit isoforms permits the formation enzymes, AalphaCalpha, AalphaCbeta, AbetaCalpha, AbetaCbeta, could theory give rise holoenzymes. Differences between...
Microbial cocultivation has been applied as a strategy to induce the biosynthesis of specialized metabolites. However, most previous studies have focused on competitive interactions between test strains. During our LC-MS-based chemical screening randomized cocultures Basidiomycetous fungi, we discovered that coculture Phellinus orientoasiaticus (Hymenochaetaceae) and Xylodon flaviporus (Schizoporaceae) induces multiple metabolites, although they did not show any morphology. Targeted...
Mass transport in diffusive gradients thin-film passive samplers is restricted to diffusion through a gel layer of agarose or cross-linked polyacrylamide (APA). The coefficient,
Host–guest formation between N3O2-donor macrocyclic hosts and lipophilic organic acid guests (that are themselves potential metal-ion ligands/extractants) has been investigated the implications of such ligand assemblies for binding metal ions have probed. The 2 ∶ 1 (organic macrocycle) demonstrated using NMR titration experiments in deuterochloroform 4-tert-butylbenzoic, palmitic, phenylphosphinic, diphenylphosphinic salicylic acids, with evidence additional intermediates some cases....
Complex mixtures of plant-derived triglycerol (TG) lipids are commonly used as feedstock components for the production industrial polymers. However, there remains a need development analytical strategies to investigate intrinsic intermolecular cross-linking reactivity individual TG molecules within these function their structures and physicochemical properties, characterization resultant products. Here, address this need, we describe novel multistage tandem mass spectrometry based method...
Abstract Background Monitoring the blood coagulation status of patients with coagulopathy or on anticoagulant therapy is important for informed treatment decisions. Quasi-static acoustic tweezing thromboelastometry (QATT) can monitor changes in using a small drop. Here, we develop heparinase and functional fibrinogen QATT assays. Methods Citrated whole (WB) samples were collected from 20 healthy volunteers IRB-approved protocols No. 520566 944474. Half used fibrinogen, platelet count tests...
Nonenzymatic reactions, though critical in natural product biosynthesis, are significantly challenging to control. Adding 3% NaI the culture medium of