应哈工大生命科学与生物技术学院戴志飞教授邀请，日本奈良先端科学技术大学菊池纯一教授讲学将于12月22日下午2：00在理学楼308会议室进行讲学活动，欢迎广大师生届时参加！
Novel Organic-Inorganic Hybrid Nanomaterial "Cerasome". Versatile Functions as Biomembrane Models, Gene Carriers,
and Molecular Devices.
Jun-ichi Kikuchi
Graduate School of Materials Science, Nara Institute of Science and Technology (NAIST),
Nara 630-0192, JAPAN
E-mail: jkikuchi@ms.naist.jp
The Cerasome is a bioinspired colloidal particle having an inner aqueous compartment like the liposomal membrane but its surface is covered with the inorganic silicate framework. The Cerasome-forming lipids were designed to have a tripartite structure; a trialkoxysilyl head, a hydrophobic double-chain segment, and a connecter unit between these moieties. Under the conditions of sol-gel reaction for the lipids in aqueous media, the Cerasomes with various sizes were prepared. Upon ultrasonication of the aqueous dispersion of the multi-walled Cerasomes, the small unilamellar Cerasomes with a diameter of c.a. 50 nm were formed. On the other hand, formation of the cell-sized Cerasomes was observed by applying the procedure to form the giant liposomes.
Currently, our attention has been focused on the functional silulation of a biological signal transduction system by using artificial self-organized assemblies in an aqueous media. From the viewpoint of supramolecular chemistry, the signal transduction appearing on the biomembrane surface can be understood as a naturally occurring supramolecular device, in which the intermolecular communication among the functional biomolecules, such as receptors and enzymes, was efficiently achieved on the lipid bilayer membrane platform. On these grounds we designed an artificial supramolecular device on artificial cell membranes. The system is basically composed of three supramolecular elements: a bilayer-forming lipid, a molecular switch, and an enzyme. The molecular switch was designed so as to tune the enzymatic activity, depending on the molecular recognition of the switch toward an input signal. As the species for tuning, we selected metal ions capable of binding to both the enzyme and the molecular switch, and also capable of affecting the catalytic activity upon binding to the enzyme. In addition, it is required that the metal-binding affinity of the molecular switch is changed in the presence and absence of an input signal. Marked signal transduction behavior was observed in the Cerasome system containing a synthetic steroidal receptor with an amino group as a molecular switch, pyridoxal 5’-phosphate as an input signal, Cu2+ ion as a mediator species, and L-lactate dehydrogenase as an enzyme.
In conclusion, the Cerasome is a versatile nanomaterial which has a potential for constructing novel biomembrane models, gene carriers, and molecular devices.
REFERENCES
[1] Katagiri, K., Ariga, K., and Kikuchi, J. Chem. Lett., (1999) 661.
[2] Hashizume, M., Kawanami, S., Iwamoto, S., Isomoto, T., and Kikuchi, J. Thin Solid Films, 438-439 (2003) 23.
[3] Hashizume, M., Inoue, H., Katagiri, K., Ikeda, A., and Kikuchi, J. J. Sol-Gel Sci. Technol., 31 (2004) 99.
[4] Katagiri, K., Hamasaki, R., Ariga, K., and Kikuchi, J. Langmuir, 18 (2002) 6709.
[5] Katagiri, K., Hamasaki, R., Hashizume, M., Ariga, K., and Kikuchi, J. J. Sol-Gel Sci. Technol., 31 (2004) 59.
[6] Katagiri, K., Hamasaki, R., Ariga, K., and Kikuchi, J. J. Am. Chem. Soc., 124 (2002) 7892.
[7] Matsui, K., Sando, S., Sera, T., Aoyama, Y., Sasaki, Y., Komatsu, T., Terashima, T., and Kikuchi, J.
J. Am. Chem. Soc., 128 (2006) 3114.
[8] Sasaki, Y., Matsui, K., Aoyama, Y., and Kikuchi, J. Nature Protocols, 1 (2006) 1227.
[9] Katagiri, K., Hamasaki, R,. Ariga, K., and Kikuchi, J. J. Sol-Gel Sci. Technol., 26 (2003) 393.
[10] Hashizume, M., Yamada, M., Katagiri, K., Tsuji, M., and Kikuchi, J. Bioconjugate Chem., 17 (2006) 1099.
[11] Tian, W.-J., Sasaki, Y., Fan, S.-D., and Kikuchi, J., Supramol. Chem., 17 (2005) 113.
[12] Sasaki, Y., Yamada, M., Terashima, T., Wang, J.-F., Hashizume, M., Fan, S.-D., and Kikuchi, J., Kobunshi Ronbunshu, 61 (2004) 541.
Novel Organic-Inorganic Hybrid Nanomaterial "Cerasome". Versatile Functions as Biomembrane Models, Gene Carriers,
and Molecular Devices.
Jun-ichi Kikuchi
Graduate School of Materials Science, Nara Institute of Science and Technology (NAIST),
Nara 630-0192, JAPAN
E-mail: jkikuchi@ms.naist.jp
The Cerasome is a bioinspired colloidal particle having an inner aqueous compartment like the liposomal membrane but its surface is covered with the inorganic silicate framework. The Cerasome-forming lipids were designed to have a tripartite structure; a trialkoxysilyl head, a hydrophobic double-chain segment, and a connecter unit between these moieties. Under the conditions of sol-gel reaction for the lipids in aqueous media, the Cerasomes with various sizes were prepared. Upon ultrasonication of the aqueous dispersion of the multi-walled Cerasomes, the small unilamellar Cerasomes with a diameter of c.a. 50 nm were formed. On the other hand, formation of the cell-sized Cerasomes was observed by applying the procedure to form the giant liposomes.
Currently, our attention has been focused on the functional silulation of a biological signal transduction system by using artificial self-organized assemblies in an aqueous media. From the viewpoint of supramolecular chemistry, the signal transduction appearing on the biomembrane surface can be understood as a naturally occurring supramolecular device, in which the intermolecular communication among the functional biomolecules, such as receptors and enzymes, was efficiently achieved on the lipid bilayer membrane platform. On these grounds we designed an artificial supramolecular device on artificial cell membranes. The system is basically composed of three supramolecular elements: a bilayer-forming lipid, a molecular switch, and an enzyme. The molecular switch was designed so as to tune the enzymatic activity, depending on the molecular recognition of the switch toward an input signal. As the species for tuning, we selected metal ions capable of binding to both the enzyme and the molecular switch, and also capable of affecting the catalytic activity upon binding to the enzyme. In addition, it is required that the metal-binding affinity of the molecular switch is changed in the presence and absence of an input signal. Marked signal transduction behavior was observed in the Cerasome system containing a synthetic steroidal receptor with an amino group as a molecular switch, pyridoxal 5’-phosphate as an input signal, Cu2+ ion as a mediator species, and L-lactate dehydrogenase as an enzyme.
In conclusion, the Cerasome is a versatile nanomaterial which has a potential for constructing novel biomembrane models, gene carriers, and molecular devices.
REFERENCES
[1] Katagiri, K., Ariga, K., and Kikuchi, J. Chem. Lett., (1999) 661.
[2] Hashizume, M., Kawanami, S., Iwamoto, S., Isomoto, T., and Kikuchi, J. Thin Solid Films, 438-439 (2003) 23.
[3] Hashizume, M., Inoue, H., Katagiri, K., Ikeda, A., and Kikuchi, J. J. Sol-Gel Sci. Technol., 31 (2004) 99.
[4] Katagiri, K., Hamasaki, R., Ariga, K., and Kikuchi, J. Langmuir, 18 (2002) 6709.
[5] Katagiri, K., Hamasaki, R., Hashizume, M., Ariga, K., and Kikuchi, J. J. Sol-Gel Sci. Technol., 31 (2004) 59.
[6] Katagiri, K., Hamasaki, R., Ariga, K., and Kikuchi, J. J. Am. Chem. Soc., 124 (2002) 7892.
[7] Matsui, K., Sando, S., Sera, T., Aoyama, Y., Sasaki, Y., Komatsu, T., Terashima, T., and Kikuchi, J.
J. Am. Chem. Soc., 128 (2006) 3114.
[8] Sasaki, Y., Matsui, K., Aoyama, Y., and Kikuchi, J. Nature Protocols, 1 (2006) 1227.
[9] Katagiri, K., Hamasaki, R,. Ariga, K., and Kikuchi, J. J. Sol-Gel Sci. Technol., 26 (2003) 393.
[10] Hashizume, M., Yamada, M., Katagiri, K., Tsuji, M., and Kikuchi, J. Bioconjugate Chem., 17 (2006) 1099.
[11] Tian, W.-J., Sasaki, Y., Fan, S.-D., and Kikuchi, J., Supramol. Chem., 17 (2005) 113.
[12] Sasaki, Y., Yamada, M., Terashima, T., Wang, J.-F., Hashizume, M., Fan, S.-D., and Kikuchi, J., Kobunshi Ronbunshu, 61 (2004) 541.
