Mass Spectrometry Analysis of Dynamics and Interactions of the LPS Translocon LptDE

Spontaneous Reaction of Oleacein and Oleocanthal with Primary Amines: A Biochemical Perspective

Oleacein (Olea) and Oleocanthal (Oleo) are two phenolic compounds found in olive oil. Cell and animal studies have shown these two compounds can modulate inflammation, cancer, and neurodegenerative diseases. Unfortunately, the study of the pharmacokinetics of these two compounds appears difficult due to their high reactivity with primary amines. Indeed, the presence of primary amines in culture media and biological fluids raises the question as to whether the observed biological effects are attributable to the parent compounds or to their amine derivatives. In the present work, we investigated the adduct formation between Olea or Oleo and tris(hydroxymethyl)aminomethane (Tris), a well-known primary amine used primarily as a buffer system, showing that the reaction kinetics were extremely rapid. In addition, we assessed whether the newly formed Tris adducts, i.e., Olea-Tris and Oleo-Tris, retained their antioxidant capacity by means of the ABTS and DPPH radical scavenging assays, showing that their activity was partially maintained. Finally, we evaluated the anti-inflammatory activity of these adducts on murine BV-2 microglial cells stimulated with lipopolysaccharide (LPS) and kept in an amine-free culture medium, showing how the biological response varied as the compound was degraded. Taken together, these data demonstrate that the biological effects reported in the literature are mainly due to the amino-derivatives of Olea and Oleo rather than the polyphenols derived from their breakdown (tyrosol and hydroxytyrosol).

Design of Benzyl-triazolopyrimidine-Based NADPH Oxidase Inhibitors Leads to the Discovery of a Potent Dual Covalent NOX2/MAOB Inhibitor

NADPH oxidases (NOXs) are enzymes dedicated to reactive oxygen species (ROS) production and are implicated in cancer, neuroinflammation, and neurodegenerative diseases. VAS2870 is a covalent inhibitor of mainly NOX2 and NOX5. It alkylates a conserved active-site cysteine, blocking productive substrate binding. To enhance potency and selectivity toward NOXs, we conducted some chemical modifications, leading to the discovery of compound 9a that preferentially inhibits NOX2 with an IC50 of 0.155 μM, and only upon its preactivation. We found that 9a, bearing a pargyline moiety, is also able to selectively inhibit MAOB over MAOA (465-fold) with an IC50 of 0.182 μM, being the first-in-class dual NOX2/MAOB covalent inhibitor. Tested in the BV2 microglia neuroinflammation model, 9a decreased ROS production and downregulated proinflammatory cytokines as iNOS, IL-1β, and IL-6 expression more efficiently than the single target inhibitors (rasagiline for MAOB and VAS2870 for NOXs) but also, more importantly, than their combination.

The role of structural biology in the design of sirtuin activators

Sirtuins are NAD+-dependent protein lysine deacylases and mono-ADP-ribosylases whose activity regulates different pathways, including DNA damage repair, cell survival and metabolism, reactive oxygen species (ROS) detoxification, inflammation, cardiac function, and neuronal signaling. Considering the beneficial effects of specific sirtuin isoforms on health and lifespan, the past two decades have seen a mounting interest in the development of sirtuin activators. The availability of enzyme-activator co-crystal structures has proven significant throughout the years for elucidating the mechanisms of action of activators and designing more potent and selective molecules. In this review, we highlight the most interesting examples of sirtuin activators and provide comprehensive coverage of the role that structural biology played in their discovery and characterization.

Native mass spectrometry-directed drug discovery: Recent advances in investigating protein function and modulation

Native mass spectrometry (nMS) is a biophysical method for studying protein complexes and can provide insights into subunit stoichiometry and composition, protein-ligand, and protein-protein interactions (PPIs). These analyses are made possible by preserving non-covalent interactions in the gas phase, thereby allowing the analysis of proteins in their native state. Consequently, nMS has been increasingly applied in early drug discovery campaigns for the characterization of protein-drug interactions and the evaluation of PPI modulators. Here, we discuss recent developments in nMS-directed drug discovery and provide a timely perspective on the possible applications of this technology in drug discovery.