Diversity, Complexity, and Specificity of Bacterial Lipopolysaccharide (LPS) Structures Impacting Their Detection and Quantification.

Endotoxins are toxic lipopolysaccharides (LPSs), extending from the outer membrane of Gram-negative bacteria and notorious for their toxicity and deleterious effects. The comparison of different LPSs, isolated from various Gram-negative bacteria, shows a global similar architecture corresponding to a glycolipid lipid A moiety, a core oligosaccharide, and outermost long O-chain polysaccharides with molecular weights from 2 to 20 kDa. LPSs display high diversity and specificity among genera and species, and each bacterium contains a unique set of LPS structures, constituting its protective external barrier.

The C-terminal domains of the NMDA receptor: How intrinsically disordered tails affect signalling, plasticity and disease.

NMDA receptors are part of the ionotropic glutamate receptor family, and are crucial for neurotransmission and memory. At the cellular level, the effects of activating these receptors include long-term potentiation (LTP) or depression (LTD). The NMDA receptor is a stringently gated cation channel permeable to Ca , and it shares the molecular architecture of a tetrameric ligand-gated ion channel with the other family members.

In-Cell Solid-State NMR: An Emerging Technique for the Study of Biological Membranes.

Biological molecular processes are often studied in model systems, which simplifies their inherent complexity but may cause investigators to lose sight of the effects of the molecular environment. Information obtained in this way must therefore be validated by experiments in the cell. NMR has been used to study biological cells since the early days of its development.

A (2)H magic-angle spinning solid-state NMR characterisation of lipid membranes in intact bacteria.

This work proposes a new approach to characterize cell membranes in intact cells by (2)H solid-state nuclear magnetic resonance (NMR) in only a few hours using magic-angle spinning (MAS) and spectral moment analysis. The method was first validated on model dipalmitoylphosphatidylcholine (DPPC) membranes, allowing the detection of lipid fluctuations below the main transition temperature. Then the lipid dynamics in Escherichia coli membranes was compared in bacteria grown under different diets.