Micelle-to-vesicle transition of an iron-chelating microbial surfactant, marinobactin E

Tate Owen, Roger Pynn, Jennifer S. Martinez, Alison Butler

Research output: Contribution to journalArticlepeer-review

39 Scopus citations


Small-angle neutron scattering (SANS) and dynamic light scattering (DLS) techniques have been applied to study the self-assembly processes of a microbially produced siderophore, marinobactin E (M E). M E is one of a series of marinobactins A-E that facilitate Fe(III) acquisition by the source bacterium through coordination of Fe(III) by the marinobactin headgroup. M E is a six-amino-acid peptide amphiphile appended by palmitic acid (C 16), and differs only in the nature of the fatty acid moiety from the other marinobactins. APO-M E (uncoordinated M E) assembles to form micelles with an average diameter of 4.0 nm. Upon coordination of one equivalent of Fe(III), the mean micellar diameter of Fe(III)-M E shrinks to ∼2.8 nm. However, in the presence of excess Fe(III), Fe(III)-M E undergoes a micelle-to-vesicle transition (MVT). At a small excess of Fe(III) over Fe(III)-M E (i.e., <1.2 Fe(III)/M E), a fraction of the Fe(III)-M E micelles rearrange into ∼200 nm diameter unilamellar vesicles. At even greater Fe(III)/M E ratios (e.g., 2-3) multilamellar aggregates begin to emerge, consistent with either multilamellar vesicles or lamellar stacks. The MVT exhibited by M E may represent a unique mechanism by which marine bacteria may detect and sequester iron required for growth.

Original languageEnglish (US)
Pages (from-to)12109-12114
Number of pages6
Issue number26
StatePublished - Dec 20 2005
Externally publishedYes

ASJC Scopus subject areas

  • General Materials Science
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Spectroscopy
  • Electrochemistry


Dive into the research topics of 'Micelle-to-vesicle transition of an iron-chelating microbial surfactant, marinobactin E'. Together they form a unique fingerprint.

Cite this