Wr. Bowen et al., DIRECT MEASUREMENT OF INTERACTIONS BETWEEN ADSORBED PROTEIN LAYERS USING AN ATOMIC-FORCE MICROSCOPE, Journal of colloid and interface science, 197(2), 1998, pp. 348-352
An atomic force microscope (AFM) in conjunction with the colloid probe
technique has been used to measure directly the interaction of adsorb
ed layers of the protein bovine serum albumin (BSA). The BSA was adsor
bed on both a silica colloid probe and a silica surface. Measurements
of force-distance curves were made at various salt concentrations and
pHs. The measured force-distance curves were in good quantitative agre
ement with predictions based on the DLVO theory using zeta potentials
(outer Helmholtz plane potentials) calculated for BSA from an independ
ently validated site-binding-site-dissociation surface model. The pape
r hence provides a direct confirmation that the AFM colloid probe tech
nique can provide a useful means of directly quantifying the interacti
on of biological macromolecules. (C) 1998 Academic Press.