Applied Biochemistry and Biotechnology

, Volume 150, Issue 3, pp 243–257

Non-Selective Toxicological Effects of the Insect Juvenile Hormone Analogue Methoprene. A Membrane Biophysical Approach

  • João P. Monteiro
  • Romeu A. Videira
  • Manuel J. Matos
  • Augusto M. Dinis
  • Amália S. Jurado
Article

DOI: 10.1007/s12010-007-8127-6

Cite this article as:
Monteiro, J.P., Videira, R.A., Matos, M.J. et al. Appl Biochem Biotechnol (2008) 150: 243. doi:10.1007/s12010-007-8127-6
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Abstract

The Gram-positive bacterium, Bacillus stearothermophilus, was used as a model organism to identify the non-selective toxic effects of the currently used insecticide methoprene (isopropyl(2E,4E)-11-methoxy-3,7,11-trimethyl-2,4-dodecadienoate). A significant decrease of the yield of bacterial cultures and a premature appearance of ultrastructural abnormalities in cells cultured in the presence of the insecticide were taken as indicators of cytotoxicity. A putative correlation of this cytotoxicity with methoprene-induced perturbations on membrane lipid organization was investigated, using differential scanning calorimetry and the fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) and its propionic acid derivative (DPH–PA). The membrane physical effects depended on the lipid bilayer composition and packing. The most striking effect was a progressive broadening and shifting to lower temperatures, with increasing methoprene concentrations, of the main transition phase of the dimyristoyl- or dipalmitoylphosphatidylcholine bilayers and of the lateral phase separation of liposomes reconstituted with the lipid extracts of B. stearothermophilus.

Keywords

MethopreneLipid dynamicsDifferential scanning calorimetryFluorescence polarizationCell ultrastructureBacillus stearothermophilus

Abbreviations

DMPC

dimyristoylphosphatidylcholine

DPH

1,6-diphenyl-1,3,5-hexatriene

DPH-PA

3-(p-(6-phenyl)-1,3,5-hexatrienyl)phenylpropionic acid

DPPC

dipalmitoylphosphatidylcholine

DSC

differential scanning calorimetry

TEM

transmission electron microscopy

Copyright information

© Humana Press Inc. 2008

Authors and Affiliations

  • João P. Monteiro
    • 1
  • Romeu A. Videira
    • 2
  • Manuel J. Matos
    • 1
  • Augusto M. Dinis
    • 3
  • Amália S. Jurado
    • 1
    • 4
  1. 1.Centro de Neurociências e Biologia Celular; Department of BiochemistryUniversity of CoimbraCoimbraPortugal
  2. 2.Higher School of TechnologyPolytechnic Institute of ViseuViseuPortugal
  3. 3.Laboratório de Microscopia Electrónica, Department of BotanyUniversity of CoimbraCoimbraPortugal
  4. 4.Department of BiochemistryUniversity of CoimbraCoimbraPortugal