Title

Lipid Rafts in the Bovine Milk Fat Globule Membrane Revealed by the Lateral Segregation of Phospholipids and Heterogeneous Distribution of Glycoproteins

Author Info

Christelle Lopez, Science et Technologie du Lait et de l’Oeuf
Marie-Noëlle Madec, Science et Technologie du Lait et de l’Oeuf
Rafael Jiménez-Flores, California Polytechnic State University - San Luis ObispoFollow

Publication Date

5-1-2010

Recommended Citation

Postprint version. Published in Food Chemistry, Volume 120, Issue 1, May 1, 2010, pages 22-33.

The definitive version is available at https://doi.org/10.1016/j.foodchem.2009.09.065.

Abstract

This study reveals the lateral organisation of the milk fat globule membrane (MFGM). Using confocal laser scanning microscopy (CLSM) and a lipid soluble molecule, an exogenous phospholipid and two lectins as fluorescent probes we located triacylglycerols in the core of fat globules and investigated the organisation of the polar lipids and glycoproteins of the MFGM, in situ in milk. Lipid rafts corresponding to the lateral segregation of sphingolipids in liquid-ordered phases surrounded by liquid-disordered domains composed by the glycerophospholipids were observed in the MFGM. These lipid rafts which correspond to rigid sphingolipid-rich domains have a circular shape at room temperature. CLSM experiments revealed that glycoproteins and glycolipids are heterogeneously distributed around fat globules and that they are not located in the lipid rafts. The characterisations performed by in depth thin sectioning of fat globules and in dynamic as a function of time revealed chemical and structural heterogeneities in the MFGM. Schematic 3D and 2D representations of the MFGM are proposed and discussed. The physiological and nutritional consequences of the lateral organisation of polar lipids and glycoproteins in the MFGM are discussed but remain to be elucidated.

Disciplines

Dairy Science

Copyright

2010 Elsevier