BOVINE SERUM-ALBUMIN CONFORMATION ON METHYL AND AMINE FUNCTIONALIZED SURFACES COMPARED BY SCANNING FORCE MICROSCOPY

We investigated the adsorption of albumin on chemically modified gold surfaces by scanning force microscopy operating both in contact and no ncontact mode. The surface modification was performed with thiol-based self-assembling molecules carrying amine or methyl groups. The albumi n on the aminoethanethiol-coated gold formed a uniform layer and singl e molecules could be distinguished. On the dodecanethiol-coated surfac e the protein adsorbed in aggregates or single isolated molecules depe nding on the incubation time. The width of the albumin molecule on bot h surfaces was similar, but the height was much lower on the amine tha n on the methyl surface. This was interpreted as a difference in the c onformation of albumin depending on the substrate, and could explain t he promotion of cell adhesion on amine-treated polymers coated with al bumin. (C) 1995 John Wiley & Sons, Inc.