Specific and non specific interactions involving Le( X ) determinant quantified by lipid vesicle micromanipulation.
Carbohydrate-carbohydrate recognition is emerging today as an important type of interaction in cell adhesion. One Ca(2+)mediated homotypic interaction between two Lewis( X ) determinants (Le( X )) has been proposed to drive cell adhesion in murine embryogenesis. Here, the adhesion energies of lipid vesicles functionalized with glycolipids bearing monomeric or dimeric Le( X ) determinants were measured in NaCl or CaCl(2) media with the micropipette aspiration technique. These experiments on Le( X ) with an environment akin to that provided by biological membrane confirmed the existence of this specific calcium dependent interaction of monomeric Le( X ). In contrast, dimeric Le( X ) produced a repulsive contribution. By using a simple model involving the various contributions to the adhesion free energy, specific and non specific interactions could be separated and quantified. The involvement of calcium ions has been discussed in the monomeric and dimeric Le( X ) lipids.
Laboratoire de Physique Statistique de l'Ecole Normale Supérieure, UMR 8550 associée au CNRS et aux universités Paris 6 et Paris 7, France.
Christine
C
Gourier
Frédéric
F
Pincet
Eric
E
Perez
Yongmin
Y
Zhang
Jean-Maurice
JM
Mallet
Pierre
P
Sinaÿ
D002118:Calcium / Q000378:metabolism; D002122:Calcium Chloride; D016256:Lewis X Antigen / Q000737:chemistry / Q000378:metabolism*; D008081:Liposomes / Q000378:metabolism*; D012965:Sodium Chloride
D016256:Lewis X Antigen; D008081:Liposomes; D012965:Sodium Chloride; D002122:Calcium Chloride; D002118:Calcium