Protein complex involved in modulation of signaling and synaptic function in the brain, predominantly in the cerebral cortex and hippocampus. Forms dimers and multimers of amyloid beta peptide 40 and peptide 42 (proteolytic cleavage products of amyloid beta A4 protein, also known as amyloid beta precursor protein). Mostly found in the extracellular space with a proportion occurring as membrane-bound species. Influences synaptic plasticity through various receptors, mediates dendritic spine loss leading to decreased synapse density, inhibits long-term potentiation (LTP) and enhances long-term depression (LTD). Soluble multimeric form is the main pathogenic species linked to Alzheimer's disease.
amyloid-beta protein 40/42 complex