Energetic portrait of the amyloid beta transition state

In this study we use massively parallel combinatorial mutagenesis, a kinetic selection assay, and machine learning to better understand the nucleation reaction of amyloid beta (Aꞵ42), the protein that aggregates as a hallmark of Alzheimer’s disease (AD) and is mutated to cause familial AD. Systematic measurement of the nucleation of mutations at Amyloid beta 1-42 (AB1-42). We constructed mutagenesis libraries containing: double amino acid mutations at AB1-28 (N_terminal_Ab42_double_mutants), or double amino acid mutations at AB28-42 (C_terminal_Ab42_double_mutants), or combinatorial mutations with DTS codon mutagenesis (Combinatorial_1 and Combinatorial_2). The selection experiment to quantify amyloid nucleation for each library was performed in 3 biological replicates, each of them with one input sample (before selection) and one output sample (after selection).