1,3-propanediol binds deep inside the channel to inhibit water permeation through aquaporins.
Yu L, Rodriguez RA, Chen LL, Chen LY, Perry G, McHardy SF, Yeh CK. 1,3-propanediol binds deep inside the channel to inhibit water permeation through aquaporins. Protein Sci. 2016 Feb; 25(2):433-41.