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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

The Self-Assembly of a Cyclic Lipopeptides Mixture Secreted by a B. megaterium Strain and Its Implications on Activity against a Sensitive Bacillus Species

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Author(s):
Pueyo, Manuel T. [1] ; Mutafci, Bruna A. [1] ; Soto-Arriaza, Marco A. [2] ; Di Mascio, Paolo [1] ; Carmona-Ribeiro, Ana M. [1]
Total Authors: 5
Affiliation:
[1] Univ Sao Paulo, Inst Quim, Dept Bioquim, BR-01498 Sao Paulo - Brazil
[2] Pontificia Univ Catolica Chile, Dept Quim Fis, Santiago - Chile
Total Affiliations: 2
Document type: Journal article
Source: PLoS One; v. 9, n. 5 MAY 9 2014.
Web of Science Citations: 4
Abstract

Cyclic lipopeptides are produced by a soil Bacillus megaterium strain and several other Bacillus species. In this work, they are detected both in the Bacillus intact cells and the cells culture medium by MALDI-TOF mass spectrometry. The cyclic lipopeptides self-assemble in water media producing negatively charged and large aggregates (300-800 nm of mean hydrodynamic radius) as evaluated by dynamic light scattering and zeta-potential analysis. The aggregate size depends on pH and ionic strength. However, it is not affected by changes in the osmolarity of the outer medium suggesting the absence of an internal aqueous compartment despite the occurrence of low molecular weight phospholipids in their composition as determined from inorganic phosphorus analysis. The activity against a sensitive Bacillus cereus strain was evaluated from inhibition halos and B. cereus lysis. Essential features determining the antibiotic activity on susceptible Bacillus cereus cells are the preserved cyclic moiety conferring cyclic lipopeptides resistance to proteases and the medium pH. The aggregates are inactive per se at the pH of the culture medium which is around 6 or below. The knock out of the sensitive cells only takes place when the aggregates are disassembled due to a high negative charge at pH above 6. (AU)

FAPESP's process: 12/12663-1 - Singlet molecular oxygen and peroxides in chemical biology
Grantee:Paolo Di Mascio
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 06/56530-4 - Carbonilic and redox stress associated with alpha-aminoketones and endogenous beta-ketoacids: mechanisms and biomarkers.
Grantee:Etelvino José Henriques Bechara
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 11/00046-5 - Interactions between membranes, biomolecules and surfaces
Grantee:Ana Maria Carmona-Ribeiro
Support Opportunities: Regular Research Grants
FAPESP's process: 13/07937-8 - Redoxome - Redox Processes in Biomedicine
Grantee:Ohara Augusto
Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC