The role molecular chirality plays in tubule formations is probed through the development of a new class of tubule-forming lipids. While the new compounds produce tubules under the same mild conditions as does the prototypical tubule-forming compound, DC(8,9)PC, several important morphological differences appear in tubules formed by these compounds. Atomic force- and optical microscopy show the new tubules' diameters to be about twice as great as those made with DC(8,9)PC, which can be interpreted in accordance with a "chiral packing" class of tubule structure theory. As with DC(8,9)PC, a helical trace is found upon the new compounds' tubule exteriors, imparting a sense of chirality to these microscopic cylinders. Surprisingly, enantiomerically-pure preparations of the new compounds contain helices of both chiral senses, contrary to the heretofore-observed relationship between tubule helix handedness and phospholipid chirality, and inconsistent with the chiral packing theory. Another unexpected result is that one of the new tubule-forming molecules can generate tubules with diameters some ten times of that of those previously reported.
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