Application of the Quartz Crystal Microbalance to the Study of Multivalent Carbohydrate–Carbohydrate Adhesion

RODRÍGUEZ SEGUÍ, S. A. ; BUCIOR, I.; BURGER, M. M.; ERRACHID, A.; FERNÀNDEZ-BUSQUETS, X.

SENSOR LETTERS

AMER SCIENTIFIC PUBLISHERS

Año: 2009 vol. 7 p. 782 - 787

1546-198X

Carbohydrate-carbohydrate interactions in cell adhesion are being increasingly explored as important players in cel-cell and cell-extracellular matrix interactions that are characterized by finely tuned on-off rates. The emerging field of glycomics requires the application of new methodologies to the study of the generally weak and multivalent carbohydrate binding sites. Here we use the quartz crystal microbalance (QCM) for the analysis of the self-binding activity of the g200 glycan, a molecule of marine sponge origin that is responsible for Ca2+-dependent species-specific cell adhesion. The QCM has the advantages over other highly sensitive techniques of having only one of the interacting partners bound to a surface, and of lacking microfluidics circuits prone to be clogged by self-aggregating glycans. Our results show that g200 self-interaction is negligible in the absence of Ca2+. Different association kinetics at low and high Ca2+ concentrations suggest the existence of two different Ca2+ binding sites in g200. Finally, the observation of a non-saturable binding indicates that g200 has more than one self-adhesion site per molecule. This work represents the first report to date using the QCM to study carbohydrate-carbohydrate interactions involved in cell adhesion.