Adsorption of Amyloid Beta Peptide by Metal-Organic Frameworks

Metal-organic frameworks (MOFs) are capable of adsorbing a wide range of molecules. In addition to the more commonly investigated small molecules, researchers have demonstrated that MOFs adsorb much larger molecules, such as proteins and peptides. We have investigated whether MOFs are capable of adsorbing amyloid beta peptide. Amyloid beta plays a pivotal role in the progression of Alzheimer's disease because individual copies of the peptides can aggregate, forming neurotoxic oligomers and the amyloid plaques found in brains of Alzheimer's patients. After synthesizing a number of commonly studied MOFs, their adsorption capabilities were tested. We found that the MOFs tested readily adsorbed small amounts of amyloid beta (as determined by gel electrophoresis). It was determined that in most cases, adsorption occurs rapidly, with complete adsorption within minutes of incubation. Overall adsorption capacity was found to vary between different MOFs as well. Once adsorbed, amyloid beta peptide can subsequently be eluted from some MOFs by treatment with acetonitrile/water solutions, though retention strength varied between different MOFs. In some cases, MOFs that showed complete adsorption also saw high levels of peptide elution, but others showed little to no elution of the peptide. Together these data can help us begin to understand the interactions between amyloid beta and MOFs.