Toxicity of fatty acid hydroperoxides towards Yarrowia lipolytica: implication of their membrane fluidizing action.
Linoleic acid hydroperoxide (HPOD), substrate of hydroperoxide lyase, an enzyme of the lipoxygenase pathway, can be transformed into many aromatic compounds, the so-called "green notes". The presence of linoleic acid hydroperoxide in the culture medium of Yarrowia lipolytica, the yeast expressing the cloned hydroperoxide lyase of green bell pepper, undoubtedly exerted an inhibition on the growth and a toxic effect with 90% of yeast cells died after 120 min of exposition in 100 mM HPOD solution. The increase in cell membrane fluidity evaluated by measuring fluorescence generalized polarization with the increasing concentration of HPOD in the medium confirmed the fluidizing action of HPOD on yeast membrane. In addition, we determined by infrared spectroscopy measurement that this compound rapidly diffused into model phospholipids [1, 2-Dimyristoyl-D54-sn-Glycero-3-Phosphocholine (DMPC-D54)] bilayer, modifying their general physical state and their phase transition. In the presence of various concentrations of HPOD, the phase transition of DMPC-D54 occurred with an increase of both the corresponding wave number shift and the temperature range but the phase transition temperature was not modified. These results show that the toxic effects of HPOD on the yeast Yarrowia lipolytica may be initially linked to a strong interaction of this compound with the cell membrane phospholipids and components.
Tran Thanh
Hoa
H
Laboratoire de Génie des Procédés Microbiologiques et Alimentaires, ENSBANA, Université de Bourgogne, Campus Universitaire Montmuzard, 1, esplanade Erasme 21000 Dijon, France.
Beney
Laurent
L
Simonin
Hélène
H
Nguyen
Thi Xuan Sam
TX
Gervais
Patrick
P
Belin
Jean-Marc
JM
Husson
Florence
F
D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D008041:Linoleic Acids / Q000008:administration & dosage*; D008054:Lipid Peroxides / Q000008:administration & dosage*; D008560:Membrane Fluidity / Q000187:drug effects / Q000502:physiology*; D010743:Phospholipids / Q000378:metabolism*; D025062:Yarrowia / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*
D008041:Linoleic Acids; D008054:Lipid Peroxides; D010743:Phospholipids; C008285:linoleic acid hydroperoxide