Magic mushroom extracts in lipid membranes

Spectroscopic behavior of bufotenine and bufotenine N-oxide: Solvent and pH effects and interaction with biomembrane models

Bufotenine is a fluorescent analog of Dimethyltryptamine (DMT) that has been widely studied due to its psychedelic properties and biological activity. However, little is known about its spectroscopic properties in different media. Thus, we present in this work, for the first time, the spectroscopic behavior of bufotenine and bufotenine N-oxide by means of their fluorescence properties. Both molecules exhibit changes in optical absorption and emission spectra with variations in pH of the medium and in different solvents. Assays in the presence of biomembranes models, like micelles and liposomes, were also performed. In surfactants titration experiments, the spectral shift observed in fluorescence shows the interaction of both molecules with pre-micellar structures and with micelles. Steady state anisotropy measurements show that both bufotenine and bufotenine N-oxide, in the studied concentration range, interact with liposomes without causing changes in the fluidity of the lipid bilayer. These results can be useful in studies that aim at searching for new compounds, inspired by bufotenine and bufotenine N-oxide, with relevant pharmacological activities and also in studies that use these molecules as markers of psychiatric disorders.

The molecular basis of the antidepressant action of the magic mushroom extract, psilocin

Magic mushrooms, and their extract psilocybin, are well-known for their psychedelic properties and recreational use. Psilocin, the bio-active form of psilocybin, can potentially treat various psychiatric diseases. Psilocin putatively exerts its psychedelic effect as an agonist to the serotonin 2A receptor (5-HT2AR), which is also the receptor for the neurological hormone serotonin. The two key chemical differences between the two molecules are first, that the primary amine in serotonin is replaced with a tertiary amine in psilocin, and second, the hydroxyl group is substituted differently on the aromatic ring. Here, we find that psilocin can bind to 5-HT2AR with an affinity higher than serotonin, and provide the molecular logic behind the higher binding affinity of psilocin using extensive molecular dynamics simulations and free energy calculations. The binding free energy of psilocin is dependent upon the protonation states of the ligands, as well as that of the key residue in the binding site: Aspartate 155. We find that the tertiary amine of psilocin, and not the altered substitution of the hydroxyl group in the ring is responsible for the increased affinity of psilocin. We propose design rules for effective antidepressants based on molecular insights from our simulations.

CHARMM-GUI Membrane Builder: Past, Current, and Future Developments and Applications

Molecular dynamics simulations of membranes and membrane proteins serve as computational microscopes, revealing coordinated events at the membrane interface. As G protein-coupled receptors, ion channels, transporters, and membrane-bound enzymes are important drug targets, understanding their drug binding and action mechanisms in a realistic membrane becomes critical. Advances in materials science and physical chemistry further demand an atomistic understanding of lipid domains and interactions between materials and membranes. Despite a wide range of membrane simulation studies, generating a complex membrane assembly remains challenging. Here, we review the capability of CHARMM-GUI Membrane Builder in the context of emerging research demands, as well as the application examples from the CHARMM-GUI user community, including membrane biophysics, membrane protein drug-binding and dynamics, protein-lipid interactions, and nano-bio interface. We also provide our perspective on future Membrane Builder development.

Interaction of psychedelic tryptamine derivatives with a lipid bilayer

Naturally occurring psychedelics have been used for a long time as remedies or in religious ceremonies and recreational activities. Recent studies have proven the therapeutic potential of some psychedelic compounds to safely treat a wide range of diseases such as anxiety, depression, migraine, and addiction. It is hypothesized that psychedelic compounds like tryptamines can exert their effects by two possible mechanisms: binding to the transmembrane serotonin receptor and/or modifying the properties of the neuronal membrane that can alter the conformational equilibrium and desensitize receptors. The impact of three different tryptamine class compounds with a tertiary amine (dimethyltryptamine, bufotenine, and 5-MeO-DMT) in both neutral and charged forms on a model bilayer lipid membrane are studied using all-atom MD simulations. All compounds partition into the bilayer, and change membrane properties, but to different extents. We determine the tendency of compounds to partition into the membrane by free energy calculations. Neutral tryptamines partition into the bilayer almost completely. Dimethyltryptamine and 5-MeO-DMT cross the membrane spontaneously during the simulation time, but bufotenine does not, although it has the maximum effect on the structural properties of the membrane. However, protonated compounds partition partially into the bilayer and cannot pass through the middle of the membrane during the simulation time. In this way, subtle alteration of chemical structure can play a significant role in the improvement or deterioration of partitioning of these compounds into the bilayer and their passage across the membrane.