Category: Uncategorized

AQUEOUS MILIEU. “Structural fluctuations of most residues (particularly those directly exposed to the aqueous environment) and of the protein as a whole are slightly attenuated in D2O, in which environment the protein is also somewhat more compact than in H2O (Fig. 7b). Additional simulations on other representative systems show that the rigidifying effect of heavy water is apparent also in small soluble proteins.” https://lnkd.in/dzPDm5w View in LinkedIn

BINDING CONFIGURATION. “Figure 7b shows the time evolution of the radius of gyration of the TMD domain, while Fig. 7c and d presents the root mean square fluctuations (RMSF) of individual residues of the proteins superimposed on its structure and plotted in a graph together with the mean value of RMSF. A small but significant difference is apparent in the behavior of the protein in H2O vs D2O.” https://lnkd.in/dzPDm5w View in LinkedIn

RECEPTOR BINDING. “H2O and D2O have mutually slightly shifted densities inside the protein cavity, with H2O overlapping better than D2O with the modeled water positions. Furthermore, MD simulations show clustered water molecules close to the lactisole binding site. These internal positions may have a differential effect between H2O and D2O, though differences between the averaged water densities are not very pronounced.” https://lnkd.in/dzPDm5w View in LinkedIn

This extraordinary book was written by a man who I have been close friends with since we were 9 years old. Even then, he wanted to be an entomologist. He has been living his dream for his entire life. View in LinkedIn

NEUTRON STARS. “Recent theoretical models propose some alternatives, such as inner cores containing a mix of neutrons, protons, and exotic matter made of quarks or new combinations of quarks.” The old impossible is the new probable. https://lnkd.in/dZCjeAB View in LinkedIn

FURTHER VALIDATION. “Next, we carried out microsecond MD simulations of the TMD embedded in a phospatidylcholine (POPC) bilayer in either H2O or D2O (for details including our model of D2O effectively including nuclear quantum effects, (see SI, Tables S2–S4). Note that water molecules enter the TMD domain and cluster at positions that partially overlap with the modeled water positions, see Fig. 7a.” https://lnkd.in/dzPDm5w View in LinkedIn

MOLECULAR VALIDATION. “Fig. 7: Differences between the behavior of the transmembrane part of the human sweet taste receptor in H2O vs D2O base on analysis of three independent microsecond trajectories.” https://lnkd.in/dzPDm5w View in LinkedIn

“FUTURE STUDIES should be able to elucidate the precise sites and mechanisms of action, as well as the reason why D2O activates TAS1R2/TAS1R3 in particular, resulting in sweet (but not other) taste. To this end, site-directed mutagenesis as well as determination of the precise structure of the TAS1R2/TAS1R3 receptor will be of key importance.” https://lnkd.in/dzPDm5w View in LinkedIn

MOLECULAR DOSE RESPONSE. “Next, TAS1R2/TAS1R3 receptor along with the chimeric Gα16gust44 subunit were transiently expressed, and the functionality was illustrated by dose-dependent response to D-glucose (Fig. 6c). Finally, and in agreement with calcium imaging, we found that 10% D2O activated these cells. Activation by 100% D2O was even more pronounced (Fig. 6d).” https://lnkd.in/dzPDm5w View in LinkedIn

NUCLEAR QUANTUM EFFECT. “At a molecular level, this general behavior may be traced back to the slightly stronger hydrogen bonding in D2O vs H2O, which is due to a nuclear quantum effect, namely difference in zero-point energy. Biologically relevant situations where one may expect strong nuclear quantum effects as implications of H/D substitution directly involve proton or deuteron transfer. Unless a yet unknown indirect mechanism is involved, this is not the case for the TAS1R2/TAS1R3 sweet taste receptor, thus the nuclear quantum effect is probably weak in the present case.” https://lnkd.in/dzPDm5w View in LinkedIn