Adaptations of guest and host in expanded self-assembled capsules
- The Skaggs Institute for Chemical Biology and Department of Chemistry, The Scripps Research Institute MB-26, 10550 North Torrey Pines Road, La Jolla, CA 92037
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Contributed by Julius Rebek, Jr., August 23, 2007 (received for review August 2, 2007)
Abstract
Reversible encapsulation complexes create spaces where two or more molecules can be temporarily isolated. When the mobility of encapsulated molecules is restricted, different arrangements in space are possible, and new forms of isomerism (“social isomerism”) are created: the orientation of one encapsulated molecule influences that of the other in the confined space. Expansion of a capsule's length is possible through addition of small-molecule spacer elements. The expanded capsules have dimensions that permit the observation of social isomerism of two identical guests, and they adopt arrangements that properly fill the host's space. The host also can adapt to longer guests by incorporating additional spacers, much as protein modules are added to a viral capsid in response to larger genomes. Arachidonic and related fatty acid derivatives act in this way to induce the assembly of further extended capsules having sufficient length to accommodate them.
Footnotes
- *To whom correspondence should be addressed. E-mail: jrebek{at}scripps.edu
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Author contributions: D.A. performed research; and D.A. and J.R. wrote the paper.
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The authors declare no conflict of interest.
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This article contains supporting information online at www.pnas.org/cgi/content/full/0707759104/DC1.
- © 2007 by The National Academy of Sciences of the USA
