A helix-induced oligomeric transition of gaegurin 4, an antimicrobial peptide isolated from a Korean frog

Cited 0 time in scopus
Metadata Downloads
Title
A helix-induced oligomeric transition of gaegurin 4, an antimicrobial peptide isolated from a Korean frog
Author(s)
S Y Eun; H K Jang; S K Han; P D Ryu; B J Lee; Kyou Hoon Han; S J Kim
Bibliographic Citation
Molecules and Cells, vol. 21, no. 2, pp. 229-236
Publication Year
2006
Abstract
Gaegurin 4 (GGN4), a novel peptide isolated from the skin of a Korean frog, Rana rugosa, has broad spectrum antimicrobial activity. A number of amphipathic peptides closely related to GGN4 undergo a coil to helix transition with concomitant oligomerization in lipid membranes or membrane-mimicking environments. Despite intensive study of their secondary structures, the oligomeric states of the peptides before and after the transition are not well understood. To clarify the structural basis of its antibiotic action, we used analytical ultracentrifugation to define the aggregation state of GGN4 in water, ethyl alcohol, and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). The maximum size of GGN4 in 15% HFIP corresponded to a decamer, whereas it was monomeric in buffer. The oligomeric transition is accompanied by a cooperative 9 nm blue-shift of maximum fluorescence emission and a large secondary structure change from an almost random coil to an α-helical structure. GGN4 induces pores in lipid membranes and, using electrophysiological methods, we estimated the diameter of the pores to be exceed 7.3 ?, which suggests that the minimal oligomer structure responsible is a pentamer.
Keyword
aggregation stateanalytical ultracentrifugeantimicrobial peptidegaegurin 4
ISSN
1016-8478
Publisher
Korea Soc-Assoc-Inst
Type
Article
Appears in Collections:
1. Journal Articles > Journal Articles
Files in This Item:
  • There are no files associated with this item.


Items in OpenAccess@KRIBB are protected by copyright, with all rights reserved, unless otherwise indicated.