NMR solution structure and position of transportan in neutral phospholipid bicelles

Transportan is a chimeric cell-penetrating peptide constructed from the peptides galanin and mastoparan, which has the ability to internalize living cells carrying a hydrophilic load. In this study, we have determined the NMR solution structure and investigated the position of transportan in neutral bicelles. The structure revealed a well-defined -helix in the C-terminal mastoparan part of the peptide anti a weaker tendency to form an -helix in the N-terminal domain. The position of the peptide in relation to the membrane, as studied by adding paramagnetic probes, shows that the peptide lies parallel to, and in the head-group region of the membrane surface. This result is supported by amide proton secondary chemical shifts. (C) 2004 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.