Latest Mass Spectrometry Articles

Liu, Q.; et al. Mass spectrometry reveals high levels of hydrogen peroxide in pancreatic cancer cells. Angewandte Chemie International Edition. 2022.

Introduction

Reactive oxygen species (ROS) are critical for many cellular functions, and dysregulation of ROS involves the development of multiple types of tumors, including pancreatic cancer. However, ROS have been grouped into a single biochemical entity for a long time, and the specific roles of certain types of ROS in tumor cells (e.g., pancreatic ductal adenocarcinoma (PDAC)) have not been systematically investigated.

In this work, the authors applied a highly sensitive and accurate mass spectrometry-based method to study PDAC cells from human and genetically modified animals. The results show that the oncogenic KRAS mutation promotes the accumulation of hydrogen peroxide (H₂O₂) rather than superoxide or hydroxyl radicals in pancreatic cancer cells. The authors further identified that the enriched H₂O₂ modifies cellular metabolites and promotes the survival of pancreatic cancer cells.

Wang, Y.; et al. Performing 2D-1D-2D mass spectrometry imaging using strings. Analytical Chemistry. 2022, 94(3): 1661-1668.

Introduction

The mass spectrometry imaging (MSI) technique is widely used in several fields due to its ability to provide spatial information of samples. However, for existing MSI methods, the sample is typically placed on a two-dimensional (2D) platform and is scanned back and forth. As a result, the platform size limits the imaging size.

In this paper, the authors propose a new MSI method that involves the initial imprinting of chemicals on a two-dimensional string plane area. The string plane was then unraveled to a one-dimensional (1D) string, and the chemicals imprinted on it were ionized using a lab-made ion source. Finally, a 2D MSI image was reconstructed through data processing (2D–1D–2D mass imaging).

Vallejo, D. D.; et al. Mass spectrometry methods for measuring protein stability. Chemical reviews. 2022, 122(8): 7690-7719.

Introduction

Mass spectrometry is a central technology in the life sciences, providing our most comprehensive account of the molecular inventory of the cell. In parallel with developments in mass spectrometry technologies targeting such assessments of cellular composition, mass spectrometry tools have emerged as versatile probes of biomolecular stability.

In this review, the authors cover recent advancements in this branch of mass spectrometry that target proteins, a centrally important class of macromolecules that accounts for most biochemical functions and drug targets.

Westphall, M. S.; et al. Three-dimensional structure determination of protein complexes using matrix-landing mass spectrometry. Nature Communications. 2022, 13(1): 2276.

Introduction

Native mass spectrometry (MS) is increasingly used to provide complementary data to electron microscopy (EM) for protein structure characterization. Beyond the ability to provide mass measurements of gas-phase biomolecular ions, MS instruments offer the ability to purify, select, and precisely control the spatial location of these ions.

The authors describe a modified Orbitrap mass spectrometer system capable of depositing a native MS ion beam onto the surface of TEM grids. With this system and the use of a chemical landing matrix, they demonstrate that non-covalent gaseous ions of protein-protein complexes can retain their condensed-phase structures by obtaining a 3D reconstruction of landed particles.

Sisley, E. K.; et al. Native ambient mass spectrometry imaging of ligand-bound and metal-bound proteins in rat brain. Journal of the American Chemical Society. 2022, 144(5): 2120-2128.

Introduction

Label-free spatial mapping of the noncovalent interactions of proteins in their tissue environment has the potential to revolutionize life sciences research by providing opportunities for the interrogation of disease progression, drug interactions, and structural and molecular biology more broadly.

The authors demonstrate mass spectrometry imaging of endogenous intact noncovalent protein–ligand complexes in rat brain. The spatial distributions of a range of ligand-bound and metal-bound proteins were mapped in thin tissue sections by use of nanospray-desorption electrospray ionization. Proteins were identified directly from the tissue by top-down mass spectrometry.