Albumin-bound polyacrolein: implications for Alzheimer's disease.

Acrolein-modified proteins are markers of disorders such as Alzheimer's disease (AD). Acrolein (H2C=HC-CH=O), which can be produced by the oxidative properties of amyloid-beta (Abeta) peptide, localizes to areas immediately surrounding early Abeta aggregates. The focal production of acrolein would consequently yield localized high concentrations that may be susceptible to polymerization via basic latex polymer chemistry. Using albumin as our model we examined whether simple in vitro conditions may bring about higher order aggregates composed of polyacrolein. We observed that thin plastic-like fragments were formed following incubation of albumin in acrolein solutions from 5 to 500 mM in sodium phosphate buffers (pH 7.4). The layered plastic film stained for carbonyls and for amyloid (cross-beta structures) suggesting a polyacrolein-albumin colloidal mixture. Large structures (up to 2700 microm2) readily form under simple conditions. These observations suggest that polyacrolein latexes may potentially exist in biological tissues contributing to the pathogenesis of diseases such as AD.