Figure 1
From: A proton shelter inspired by the sugar coating of acidophilic archaea
Adaptation of the cell membrane of acidophilic archaea to a low pH.
(a) The single-layered cell membrane is highly resistant to proton permeation and can withstand a steep transmembrane pH gradient. (b) Enlarged view demonstrating the molecular structure of a tetraether lipid in which the sugar chains and phosphate group are connected to each side of two hydrocarbon chains via four ether bonds. Shown is one of the dominating sugar moieties: gulose. (c), Hydroxyl groups on the sugar moieties prevent the protons from penetrating the cell membrane, which is evidenced by the OH-rich polymer mimic.
