Dynamical Model for the Counteracting Effects of Trimethylamine N-Oxide on Urea in Aqueous Solutions under Pressure.

ABSTRACT: Of cosolutes found in living cells, urea denatures and trimethylamine N-oxide (TMAO) stabilizes proteins; furthermore, these effects cancel at a 2:1 ratio of urea to TMAO. Interestingly, cartilaginous fish use urea and TMAO as osmolytes at similar ratios at the ocean surface but with increasing fractions of TMAO at increasing depths. Here, molecular dynamics simulations of aqueous solutions with different urea:TMAO ratios show that the diffusion coefficients of water in the solutions vary with pressure if the urea:TMAO ratio is constant, but strikingly, they are almost pressure independent at the ratio found in these fish as a function of depth. This suggests that this ratio may be maintaining a homeostasis of water dynamics. In addition, diffusion is determined by hydrogen-bond lif

SUBMITTER: Teng X 

PROVIDER: S-EPMC8886402 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature