Ultraweak sugar-sugar interactions for transient cell adhesion.
Carbohydrate-carbohydrate interactions are rarely considered in biologically relevant situations such as cell recognition and 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, we confirm the existence of this specific interaction by reporting the first direct quantitative measurements in an environment akin to that provided by membranes. The adhesion between giant vesicles functionalized with Le(x) was obtained by micropipette aspiration and contact angle measurements. This interaction is below the thermal energy, and cell-cell adhesion will require a large number of molecules, as illustrated by the Le(x) concentration peak observed at the cell membranes during the morula stage of the embryo. This adhesion is ultralow and therefore difficult to measure. Such small interactions explain why the concept of specific interactions between carbohydrates is often neglected.
Laboratoire de Physique Statistique de l'Ecole Normale Supérieure, UMR 8550 associée au CNRS et aux Universités Paris 6 et Paris 7, 75231 Paris cedex 05, France.
F
F
Pincet
T
T
Le Bouar
Y
Y
Zhang
J
J
Esnault
J M
JM
Mallet
E
E
Perez
P
P
Sinaÿ
D002118:Calcium / Q000502:physiology; D002122:Calcium Chloride / Q000737:chemistry; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002448:Cell Adhesion; D007700:Kinetics; D016256:Lewis X Antigen / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D008954:Models, Biological; D008969:Molecular Sequence Data; D010713:Phosphatidylcholines / Q000737:chemistry*; D013816:Thermodynamics; D014312:Trisaccharides / Q000737:chemistry*
D016256:Lewis X Antigen; D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D014312:Trisaccharides; C027891:1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine; D002122:Calcium Chloride; D002118:Calcium