Reversible Control of Exo- and Endo-Budding Transitions in a Photosensitive Lipid Membrane

Authors

  • Ken-ichi Ishii,

    1. School of Materials Science, Japan, Advanced Institute of Science and Technology, 1–1 Asahidai, Nomi, Ishikawa 923-1292 (Japan), Fax: (+81) 761-51-1525
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  • Tsutomu Hamada Dr.,

    1. School of Materials Science, Japan, Advanced Institute of Science and Technology, 1–1 Asahidai, Nomi, Ishikawa 923-1292 (Japan), Fax: (+81) 761-51-1525
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  • Masaomi Hatakeyama Dr.,

    1. School of Knowledge Science, Japan, Advanced Institute of Science and Technology, 1–1 Asahidai, Nomi, Ishikawa 923-1292 (Japan)
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  • Ryoko Sugimoto,

    1. School of Materials Science, Japan, Advanced Institute of Science and Technology, 1–1 Asahidai, Nomi, Ishikawa 923-1292 (Japan), Fax: (+81) 761-51-1525
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  • Takeshi Nagasaki Prof.,

    1. Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan)
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  • Masahiro Takagi Prof.

    1. School of Materials Science, Japan, Advanced Institute of Science and Technology, 1–1 Asahidai, Nomi, Ishikawa 923-1292 (Japan), Fax: (+81) 761-51-1525
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Abstract

We have developed a method for the photomanipulation of lipid membrane morphology in which the shape of a vesicle can be switched by light through the use of a synthetic photosensitive amphiphile containing an azobenzene unit (KAON12). We prepared cell-sized liposomes from KAON12 and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and conducted real-time observations of vesicular transformation in the photosensitive liposome by phase-contrast microscopy. Budding transitions—either budding toward the centre of the liposome (endo-bud) or budding out of the liposome (exo-bud)—could be controlled by light. We discuss the mechanism of this transformation in terms of the change in the effective membrane surface area due to photoisomerization of the constituent molecules.

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