Structural response of G protein binding to the cyclodepsipeptide inhibitor FR900359 probed by NMR spectroscopy.

The cyclodepsipeptide FR900359 (FR) and its analogs are able to selectively inhibit the class of G proteins by blocking GDP/GTP exchange. The inhibitor binding site of G has been characterized by X-ray crystallography, and various binding and functional studies have determined binding kinetics and mode of inhibition. Here we investigate isotope-labeled FR bound to the membrane-anchored G protein heterotrimer by solid-state nuclear magnetic resonance (ssNMR) and in solution by liquid-state NMR.

Time-Resolved Ion Mobility Mass Spectrometry to Solve Conformational Changes in a Cryptochrome.

Many biological mechanisms rely on the precise control of conformational changes in proteins. Understanding such dynamic processes requires methods for determining structures and their temporal evolution. In this study, we introduce a novel approach to time-resolved ion mobility mass spectrometry.

Temporal resolution of NAIL-MS of tRNA, rRNA and Poly-A RNA is overcome by actinomycin D.

RNA is dynamically modified and has the potential to respond to environmental changes and tune translation. The objective of this work is to uncover the temporal limitation of our recently developed cell culture NAIL-MS (nucleic acid isotope labelling coupled mass spectrometry) technology and overcome it. Actinomycin D (AcmD), an inhibitor of transcription, was used in the NAIL-MS context to reveal the origin of hybrid nucleoside signals composed of unlabelled nucleosides and labelled methylation marks.

Light-guided intrabodies for on-demand target recognition in human cells.

Due to their high stability and specificity in living cells, fluorescently labeled nanobodies are perfect probes for visualizing intracellular targets at an endogenous level. However, intrabodies bind unrestrainedly and hence may interfere with the target protein function. Here, we report a strategy to prevent premature binding through the development of photo-conditional intrabodies.

Antidiabetic sulfonylureas modulate farnesoid X receptor activation and target gene transcription.

Background: The sulfonylureas glibenclamide and glimepiride are oral antidiabetic drugs that stimulate insulin secretion by closing pancreatic ATP-dependent potassium channels. The farnesoid X receptor (FXR) is a ligand-activated transcription factor that regulates the expression of several target genes involved in bile acid metabolism and lipid and glucose homeostasis.

Methods: In this study we investigated the potential effects of sulfonylureas on the signaling of FXR using a reporter-gene assay, real-time qPCR and computational methods such as molecular docking and molecular dynamic simulations.