This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Furuya, T. Articles by Ellerby, H. M. Search for Related Content PubMed PubMed Citation Articles by Furuya, T. Articles by Ellerby, H. M.

Nanotubules Formed by Highly Hydrophobic Amphiphilic -Helical Peptides and Natural Phospholipids

Tomomi Furuya^*, Taira Kiyota^*, Sannamu Lee^*,, Tohru Inoue^*, Gohsuke Sugihara^*,, Anna Logvinova, Paul Goldsmith and H. Michael Ellerby

^* Department of Chemistry, Faculty of Science, and Advanced Material Institute, Fukuoka University, Fukuoka 814-0180, Japan; and Buck Institute for Age Research, 8001 Redwood Boulevard, Novato, California 94945 USA

Correspondence: Address reprint requests to S. Lee, Dept. of Chemistry, Faculty of Science, Fukuoka University, Fukuoka 814-0180, Japan. Fax: +81-92-865-6030; E-mail: leesan{at}cis.fukuoka-u.ac.jp.

We previously reported that the 18-mer amphiphilic -helical peptide, Hel 13-5, consisting of 13 hydrophobic residues and five hydrophilic amino acid residues, can induce neutral liposomes (egg yolk phosphatidylcholine) to adopt long nanotubular structures and that the interaction of specific peptides with specific phospholipid mixtures induces the formation of membrane structures resembling cellular organelles such as the Golgi apparatus. In the present study we focused our attention on the effects of peptide sequence and chain length on the nanotubule formation occurring in mixture systems of Hel 13-5 and various neutral and acidic lipid species by means of turbidity measurements, dynamic light scattering measurements, and electron microscopy. We designed and synthesized two sets of Hel 13-5 related peptides: 1) Five peptides to examine the role of hydrophobic or hydrophilic residues in amphiphilic -helical structures, and 2) Six peptides to examine the role of peptide length, having even number residues from 12 to 24. Conformational, solution, and morphological studies showed that the amphiphilic -helical structure and the peptide chain length (especially 18 amino acid residues) are critical determinants of very long tubular structures. A mixture of -helix and ß-structures determines the tubular shapes and assemblies. However, we found that the charged Lys residues comprising the hydrophilic regions of amphiphilic structures can be replaced by Arg or Glu residues without a loss of tubular structures. This suggests that the mechanism of microtubule formation does not involve the charge interaction. The immersion of the hydrophobic part of the amphiphilic peptides into liposomes initially forms elliptic-like structures due to the fusion of small liposomes, which is followed by a transformation into tubular structures of various sizes and shapes.

This article has been cited by other articles:

				F. Fernandes, L. M. S. Loura, F. J. Chichon, J. L. Carrascosa, A. Fedorov, and M. Prieto Role of Helix 0 of the N-BAR Domain in Membrane Curvature Generation Biophys. J., April 15, 2008; 94(8): 3065 - 3073. [Abstract] [Full Text] [PDF]

				Y. A. Domanov and P. K. J. Kinnunen Antimicrobial Peptides Temporins B and L Induce Formation of Tubular Lipid Protrusions from Supported Phospholipid Bilayers Biophys. J., December 15, 2006; 91(12): 4427 - 4439. [Abstract] [Full Text] [PDF]

				H. Inouye, D. Sharma, W. J. Goux, and D. A. Kirschner Structure of Core Domain of Fibril-Forming PHF/Tau Fragments Biophys. J., March 1, 2006; 90(5): 1774 - 1789. [Abstract] [Full Text] [PDF]