BINDING STRENGTH BETWEEN CELL-ADHESION PROTEOGLYCANS MEASURED BY ATOMIC-FORCE MICROSCOPY

Measurement of binding forces intrinsic to adhesion molecules is neces sary to assess their contribution to the maintenance of the anatomical integrity of multicellular organisms. Atomic force microscopy was use d to measure the binding strength between cell adhesion proteoglycans from a marine sponge. Under physiological conditions, the adhesive for ce between two cell adhesion molecules was found to be up to 400 picon ewtons. Thus a single pair of molecules could hold the weight of 1600 cells. High intermolecular binding forces are likely to form the basis for the integrity of the multicellular sponge organism.