title: Tunable aggregation by competing biomolecular interactions.
abstract: Measurements and models are reported for Concanavalin A (ConA) mediated aggregation of dextran coated colloids that is tunable via a competing ConA-glucose interaction. Video and confocal scanning laser microscopy were used to characterize ConA adsorption to dextran colloids and quasi-2D dextran coated colloid aggregation kinetics vs [ConA] and [glucose]. ConA adsorption to, and aggregation rates of, dextran coated colloids increased from negligible values to high coverage and rapid rates for increasing [ConA] in the range 0.1-10 mM and decreasing [glucose] in the range 1-100 mM, consistent with dissociation constant estimates. Analysis of colloidal aggregation kinetics indicates ConA bridge formation is the rate-limiting step controlling the transition from slow to rapid aggregation. Our findings reveal a mechanism for tuning colloidal interactions and aggregation kinetics through specific, competitive biomolecular interactions, which lends insights into aggregation phenomena in mixed synthetic-biomaterial and biological systems.
authors.affiliation: Chemical & Biomolecular Engineering, Johns Hopkins University , Baltimore, Maryland 21218, United States.
authors.forename: Gregg A
authors.initials: GA
authors.lastname: Duncan
authors.forename: Michael A
authors.initials: MA
authors.lastname: Bevan
mesh_terms: D000327:Adsorption; D001667:Binding, Competitive; D003208:Concanavalin A / Q000737:chemistry / Q000378:metabolism*; D003911:Dextrans / Q000737:chemistry; D005947:Glucose / Q000378:metabolism*; D007700:Kinetics; D008958:Models, Molecular
chemical_list: D003911:Dextrans; D003208:Concanavalin A; D005947:Glucose