Spectroscopic investigation of the interaction between biomimetic membranes and protein aggregates

Abstract

Human diseases characterized by the deposition of insoluble extracellular proteins are referred to as amyloidoses. Such amyloidoses include Alzheimer’s disease, Parkinson’s disease, Huntington disease, and prion disease. These amyloidoses are found to have common cellular and molecular mechanisms including protein aggregation. These aggregates usually consist of fibers containing misfolded protein with a [beta]-sheet conformation, termed amyloid. The protein aggregates associated with Alzheimer’s disease are amyloid-[beta] peptides which have been linked to neuronal death through a poorly understood mechanism. In this work, the interaction between a model protein (insulin) which forms amyloid aggregates and a biomimetic membrane was studied. Specifically spectroscopy was used to detect molecular level changes occurring upon this protein-membrane interaction. It was found that oligomers and protofibrils had the most significant effect on membrane quality; significant membrane deterioration was noted in their presence.