Ca2+-induced deposition of low-density lipoprotein (LDL), intermediate-density lipoprotein (IDL), and high-density lipoprotein (HDL) at proteoheparan sulfate-modified surfaces was investigated as a function of beta-amyloid (A) presence and apolipoprotein E isoform. Presence of beta-amyloid resulted in an increased deposition, as did the E4/E4 isoform compared to the corresponding E3/E3 isoform. The results are compatible with findings reported in literature on plaque formation in Alzheimer's disease, and suggest that, although simplistic, the present model system may have some potential in biosensor studies of Alzheimer plaque formation. (C) 2004 Elsevier Inc. All rights reserved.