Abstract
Direct infusion–high-resolution mass spectrometry (DI-HRMS) allows for rapid profiling of complex mixtures of metabolites in blood, cerebrospinal fluid, tissue samples and cultured cells. Here, we present a DI-HRMS method suitable for the rapid determination of metabolic fluxes of isotopically labeled substrates in cultured cells and organoids. We adapted an automated annotation pipeline by selecting labeled adducts that best represent the majority of C and/or N-labeled glycolytic and tricarboxylic acid cycle intermediates as well as a number of their derivatives. Furthermore, valine, leucine and several of their degradation products were included. We show that DI-HRMS can determine anticipated and unanticipated alterations in metabolic fluxes along these pathways that result from the genetic alteration of single metabolic enzymes, including pyruvate dehydrogenase (PDHA1) and glutaminase (GLS). In addition, it can precisely pinpoint metabolic adaptations to the loss of methylmalonyl-CoA mutase in patient-derived liver organoids. Our results highlight the power of DI-HRMS in combination with stable isotopically labeled compounds as an efficient screening method for fluxomics.
Advion Interchim Scientific® Triversa® NanoMate® (Advion, Ithaca, NY) was utilized.
Abstract
Combinatorial electrochemistry has great promise for accelerated reaction screening, organic synthesis, and catalysis. Recently, we described a new high-throughput electrochemistry platform, colloquially named “Legion”. Legion fits the footprint of a 96-well microtiter plate with simultaneous individual control over all 96 electrochemical cells. Here, we demonstrate the versatility of Legion when coupled with high-throughput mass spectrometry (MS) for electrosynthetic product screening and quantitation. Electrosynthesis of benzophenone azine was selected as a model reaction and was arrayed and optimized using a combination of Legion and nanoelectrospray ionization MS. The combination of high-throughput synthesis with Legion and analysis via MS proves a compelling strategy for accelerating reaction discovery and optimization in electro-organic synthesis.
Advion Interchim Scientific® Triversa® NanoMate® (Advion, Ithaca, NY) was utilized.
Abstract
Most spiders deploy paralytic venom for prey capture, but adults of the Nurse´s thorn finger (Cheiracanthium punctorium) instead produce a predominantly defensive venom to safeguard their offspring. Here, we characterize the molecular repertoire of C. punctorium venom to shed light on its evolutionary history. Unlike venom in other spiders, C. punctorium venom mostly comprises neurotoxic double-domain neurotoxin 19 family (CSTX) peptides and enzymes, such as phospholipase A2 (PLA2). Comparative venomics in four spiders representing two infraorders shows that CSTXs arise following the mygalomorph–araneomorph split ~300 mya by means of ancestral gene duplication and functional specialization. A gene fusion event then appeared to have merged CSTXs from two distinct clades to form the double-domain toxin. PLA2 proteins are convergently recruited to C. punctorium to fulfil a defensive function and are strikingly similar to proalgesic PLA2 proteins in bee venom. These complex, multimodal molecular innovations in venom systems highlight nature’s tendency to use the same molecular solutions for similar ecological challenges across diverse animal lineages.
Advion Interchim Scientific® Triversa® NanoMate® (Advion, Ithaca, NY) was utilized.
Abstract
Biomaterials play an important role in medicine from contact lenses to joint replacements. High-throughput screening coupled with machine learning has identified synthetic polymers that prevent bacterial biofilm formation, prevent fungal cell attachment, control immune cell attachment and phenotype, or direct stem cell fate. In-vitro preadsorption of proteins from culture medium plays a pivotal role in controlling cell response. However, there is a paucity of studies on the screening of protein adsorption into material libraries. Here, we show how quantitative analysis of protein adsorption on a 208-member polymer microarray can be achieved using liquid extraction surface analysis, combined with an adaptation of the droplet microarray (DMA) approach and tandem mass spectrometry (LESA-MS/MS) for protein identification. This study uses a fully defined cell culture medium containing only four proteins (Essential 8) to demonstrate the feasibility of the analysis approach. Our findings show that we can generate quantitative and predictive machine learning models of protein adsorption that elucidate key polymer features that describe the relationship between surface chemistry and protein adsorption. This information is of use for the rational design of new materials with bespoke protein attachment properties for biomaterials, medical devices, or in vitro compound screening.
Advion Interchim Scientific® Triversa® NanoMate® (Advion, Ithaca, NY) was utilized.
Abstract
The Arabian saw-scaled viper (Echis coloratus) is among the snakes of highest medical relevance in the Middle East and North Africa. However, to date, its venom has been investigated in a very limited number of studies, and much remains unknown regarding its compositional and functional properties. By integrating proteotranscriptomics with bioactivity profiling, we present a comprehensive transcriptome-level catalogue of E. coloratus venom components and their associated biological activities. Our analysis identified 183 venom components belonging to 17 distinct protein families. Relative toxin abundances revealed that 92% of the venom proteome is composed of C-type lectin and C-type lectin-related protein (CTL), L-amino acid oxidase (LAAO), phospholipase A2 (PLA2), snake venom serine protease (SVSP), and snake venom metalloproteinase (SVMP), with CTL and PLA2 alone accounting for 73% of the total composition. Bioassays targeting key aspects of viperid envenomation demonstrated potent protease and PLA2 activity in a concentration-dependent manner. In contrast, Factor Xa-like, plasmin-like, and haemolytic activities were negligible. Marked cytotoxicity was observed at the highest concentration tested (i.e., 25 μg/ml) in the mammalian cell lines MDCK II and Calu-3, whereas cytotoxic effects were minimal at lower concentrations. These findings highlight the complexity and potency of E. coloratus venom, and provide a valuable foundation for improving our understanding of envenomation caused by this species.
Advion Interchim Scientific® Triversa® NanoMate® (Advion, Ithaca, NY) was utilized.
Abstract
The equilibrium dissociation constant (Kd) is a quantitative measure of the strength with which a drug binds to its receptor. Methods for determining Kd typically require a priori knowledge of protein concentration or mass. We report a simple dilution method for estimation of Kd using native mass spectrometry which can be applied to protein–ligand complexes involving proteins of unknown concentration, from complex mixtures, including direct tissue sampling.
Advion Interchim Scientific® Triversa® NanoMate® (Advion, Ithaca, NY) was utilized.
Abstract
Light stabilizers are additives that are widely used to improve the lifespan and performance of polymer materials. To develop advanced polymer materials, analytical techniques investigate the degradation mechanisms and distribution of additives in polymers are crucial. Herein, two extraction–ionization methods were used: tapping-mode scanning probe electrospray ionization (t-SPESI) and liquid extraction surface analysis (LESA). The distribution and molecular structure of the photodegradation products were investigated using polyethylene films containing two types of oligomeric hindered amine light stabilizers (o-HALS). In addition, to study the relationship between light irradiation time and the relative amount of photodegradation products, we developed a method for preparing films with multiple photodegradation regions. Mass spectrometry imaging (MSI) using t-SPESI (t-SPESI-MSI) revealed that the signal intensities of HALS decreased with the time of light irradiation, and its degradation products progressively changed. Moreover, tandem mass spectrometry (MS/MS) using LESA (LESA-MS/MS) revealed that degradation products were generated by HALS fragmentation in the polymer film. By integrating these results, we propose multiple and stepwise reactions for the formation of the photodegradation products. Results indicate that the combined use of t-SPESI-MSI and LESA-MS/MS can directly analyze and understand the photodegradation mechanism of o-HALS in polymer materials.
Advion Interchim Scientific® Triversa® NanoMate® (Advion, Ithaca, NY) was utilized.
In this application note, we present a high-throughput, automated strategy for protein and antibody characterization that addresses the need for precise, reliable analysis of therapeutic proteins. Using enzymatic digestion in 96-well plates and rapid, chromatography-free injection into high-resolution mass spectrometers, this workflow enables full sequence characterization with throughput of up to 1,000 mAbs per day.
Abstract
Stable isotope-resolved metabolomics (SIRM) can provide metabolic conversion information of specific targets; it is a powerful tool for cell metabolism studies. The common analytical platform for SIRM is chromatography-mass spectrometry, which requires a large number of cells and is not suitable for precious rare cell analysis. To study a small number of cells, we established a novel SIRM method using chip-based nanoelectrospray mass spectrometry (MS). 13C-glutamine was taken as an example; the unlabeled and 13C-labeled cells were cultured and extracted in a 96-well plate and then directly injected into MS and analyzed in full scan mode and parallel reaction monitoring (PRM) mode targeting 44 glutamine-derived metabolites and their isotopologues. To define focused metabolite-related MS2 fragments produced in the PRM, a new strategy was proposed including MS2 exact m/z matching, MS2 false positive filtering, and MS2 fragment grouping to remove the interfering MS2 ions. In total, 292 and 349 pairs of paired MS2 ions were obtained in positive and negative ionization modes, respectively. By searching spectra databases, 31 targeted metabolites with their isotopologues were identified and their characteristic product ions were confirmed for MS2 quantification. The relative quantification was achieved by MS2 quantification, which showed better sensitivity and accuracy than common MS1-based quantification. Finally, this method was applied to isocitrate dehydrogenase I-mutated glioma cells for revealing the effects of triptolide on glioma cell metabolism using U-13C-glutamine as a labeling substrate.
Advion Interchim Scientific® Triversa® NanoMate® (Advion, Ithaca, NY) was utilized.
Abstract
Investigation on the distribution of persistent organic pollutants (POPs) in aquatic organisms is of great importance for exploring the biological toxicity and health risks of environmental pollutants. In this study, a liquid extraction surface analysis mass spectrometry (LESA-MS) method was developed for rapid and in situ analysis of the spatial distribution of perfluoroalkyl substances (PFASs) in zebrafish. By combining the high-precision automated moving platform of LESA device and the high-resolution MS, quantitative analysis of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) in zebrafish tissue section were easily achieved. A tissue-specific ionization efficiency factor (TSF) strategy was also proposed to correct the matrix effect in different parts of zebrafish tissue. By using the developed method, high sensitive and efficient imaging of PFOA and PFOS in zebrafish tissue was achieved, and the distributions of PFOA and PFOS in descending order were gills, organs, roes, pelvic fin, muscle, and brain. The experimental results demonstrated that the coupling of LESA-MS method with TFS strategy is an efficient and reliable approach for monitoring the content distribution of environmental pollutants in biological tissues.
Graphical abstract
Advion Interchim Scientific® Triversa NanoMate® (Advion, Ithaca, NY) was utilized.
