Collection |

Biological Mass Spectrometry

Mass spectrometry was long considered a specialist technology for physicists and chemists, but is now used across biological research. Two major driving forces of this development are Electrospray Ionization and the Orbitrap mass analyzer. On the occasion of their 30th and 20th anniversary in 2019, we assembled this collection of Nature Communications articles. As the advances of mass spectrometry are closely connected to the emergence of proteomics, we updated this collection in 2020 to celebrate 10 years of the Human Proteome Project.

The Opinion section includes an Editorial as well as Commentaries from Matthias Mann and Alexander Makarov, giving personal accounts of the invention and evolution of Electrospray Ionization and Orbitrap, respectively. The sections Protein Mass Spectrometry and Beyond Proteins feature various applications of Electrospray Ionization- and Orbitrap-based mass spectrometry. Recent advances in characterizing the human proteome in health and disease are presented in The Human Proteome section.

Mass spectrometry (MS) enables identification of modified RNA residues, but high-throughput processing is currently a bottleneck. Here, the authors present a free and open-source database search engine for RNA MS data to facilitate reliable identification of modified RNA sequences.

Article | Open Access | | Nature Communications

Bacterial tRNA is modified by thiolation of nucleosides. Here the authors identify 2-methylthiocytidine in bacterial tRNA using nucleic acid isotope labeling coupled mass spectrometry. Exposure to methylating agents converts 2-thiocytidine to 2-methylthiocytidine, which is repaired by demethylase AlkB in vivo.

Article | Open Access | | Nature Communications

While mass spectrometry-based proteomics largely relies on digesting proteins into peptides, there is no equivalent strategy for polysaccharide analysis. Here, the authors develop a chemical approach to break down poly- into oligosaccharides and present a workflow to identify polysaccharides by oligosaccharide fingerprinting.

Article | Open Access | | Nature Communications

Targeted mass spectrometry enables reproducible and accurate lipid quantification but dedicated software tools to develop targeted lipidomics assays are lacking. Here, the authors develop a targeted lipidomics workbench and lipid knowledgebase for the streamlined generation of targeted assays.

Article | Open Access | | Nature Communications

The use of machine learning for identifying small molecules through their retention time’s predictions has been challenging so far. Here the authors combine a large database of liquid chromatography retention time with a deep learning approach to enable accurate metabolites’s identification.

Article | Open Access | | Nature Communications

Collision cross section (CCS) information can aid the annotation of unknown metabolites. Here, the authors optimize the machine-learning based prediction of metabolite CCS values and curate a 1.6 million compound CCS atlas, improving annotation accuracy and coverage for known and unknown metabolites.

Article | Open Access | | Nature Communications

Flow-injection mass spectrometry (FI-MS) enables high-throughput metabolomic profiling, but ion overload typically limits its sensitivity. Here, the authors show rapid and highly sensitive FI-MS overcoming an overload of the Orbitrap by analyzing sample-specific ion distributions.

Article | Open Access | | Nature Communications

Digital information can be stored in monomer sequences of non-natural macromolecules, but only short chains can be read. Here the authors show long multi-byte digital polymers sequenced in a moderate resolution mass spectrometer. Full sequence coverage can be attained without pre-analysis digestion or the help from sequence databases.

Article | Open Access | | Nature Communications

Establishing generic carbohydrate sequencing methods is both a major scientific challenge and a strategic priority. Here the authors show a hybrid analytical approach integrating molecular spectroscopy and mass spectrometry to resolve carbohydrate isomerism, anomeric configuration, regiochemistry and stereochemistry.

Article | Open Access | | Nature Communications

It is thought that the chances for discovery of novel natural products increase by screening rare organisms. Here the authors analyse metabolites produced by over 2300 myxobacterial strains and, indeed, find a correlation between taxonomic distance and production of distinct secondary metabolite families.

Article | Open Access | | Nature Communications

The biological functions of lipids critically depend on their highly diverse molecular structures. Here, the authors determine the mass-resolved collision cross sections of 456 sphingolipid and glycerophospholipid species, providing a reference for future structural lipidomics studies.

Article | Open Access | | Nature Communications

Measuring metabolic fluxes in cellular compartments is a challenge. Here, the authors introduce an approach to infer fluxes in mitochondria and cytosol, and find that IDH1 is the major producer of cytosolic citrate in HeLa cells and that in SDH- deficient cells citrate synthase functions in reverse.

Article | Open Access | | Nature Communications

Untargeted metabolomics detects large numbers of metabolites but their annotation remains challenging. Here, the authors develop a metabolic reaction network-based recursive algorithm that expands metabolite annotation by taking advantage of the mass spectral similarity of reaction-paired neighbor metabolites.

Article | Open Access | | Nature Communications

Lack of best practice guidelines currently limits the application of metabolomics in the regulatory sciences. Here, the MEtabolomics standaRds Initiative in Toxicology (MERIT) proposes methods and reporting standards for several important applications of metabolomics in regulatory toxicology.

Perspective | Open Access | | Nature Communications

Glycomics is gaining momentum in basic, translational and clinical research. Here, the authors review current reporting standards and analysis tools for mass-spectrometry-based glycomics, and propose an e-infrastructure for standardized reporting and online deposition of glycomics data.

Review Article | Open Access | | Nature Communications