Figure 1.

Simulations of cAMP permeation through Cx26 hemichannel at ±200 mV membrane potential. (a) Snapshot of the simulated system. Protein backbone is shown in cartoon mode and colored by the secondary structure (helix in magenta, β-sheet in yellow, loop in cyan). cAMP molecules are shown in licorice with atom color code (red, oxygen; cyan, carbon; blue, nitrogen; yellow, phosphorus). Lipids, ions, and water molecules are not shown. (b) The z coordinates of all 27 cAMP molecules during the simulations are shown in different colors. Note that the flux of cAMP is in the direction opposite to the field; thus, cAMP flux is inward (down in this figure) under +200 mV and outward under −200 mV. Data are summarized in Table 1. To see this figure in color, go online.