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1.D.90.  The Channel-forming Transmembrane Multi-block Amphiphile (CTMA) Family  

Mechanical stress is sensed by many membrane proteins, but rarely by synthetic molecules. Nevertheless, synthetic tension-responsive transmembrane multi-block amphiphiles have been shown to form transmembrane channels (Muraoka et al. 2017).   In membranes, a single-transmembrane amphiphile responds to both expanding and contracting tensions to weaken and strengthen the stacking of membrane-spanning units, respectively, and ion transport is triggered by an expanding tension to form a supramolecular channel, while little transport is observed under tensionless conditions. In contrast, a three-transmembrane amphiphile showed little spectroscopic response to tensions, likely due to weaker stacking of membrane-spanning units than the single-transmembrane amphiphile. Nevertheless, the three-transmembrane amphiphile shows ion transport by forming a unimolecular channel, even under tensionless conditions, and the ion transporting activity decreased by expanding the tension. The estimated operating force of these synthetic systems was comparable to those of mechano-sensitive proteins (Muraoka et al. 2017).

References associated with 1.D.90 family:

Muraoka, T., K. Umetsu, K.V. Tabata, T. Hamada, H. Noji, T. Yamashita, and K. Kinbara. (2017). Mechano-Sensitive Synthetic Ion Channels. J. Am. Chem. Soc. [Epub: Ahead of Print] 29077401