Molecular dynamics study of GM1 ganglioside complex with amyloid β peptide (Aβ42) in lipid membrane

Alzheimer's disease (AD) is a neurodegenerative disorder and the aggregation of amyloid β peptides (Aβ) is the hallmark of this disease. Recent experimental evidences suggested that a unique complex, mono-sialo ganglioside (GM1) bound Aβ, possesses a high potential to facilitate this protein assembly, which is considered to be the seed for such aggregation process. There are no specific atomic molecular level studies done to characterize this complex computationally to give more insight into the conformational changes and interactions between them. In this work, we have done a simulation study on amyloid β peptide (Aβ42) with GM1 ganglioside in DPPC lipid membrane. An all atom molecular dynamics simulation is performed between the above peptide and GM1 in the membrane. Our simulation analysis explores the structural changes which occur in the protein by the influence of GM1 and lipids in the membrane. Secondary structure of the peptide in Aβ42 complex shows significant changes in C-terminal region especially at the helical segment. The complex is stabilized by a number of intra- and inter-hydrogen bonds within the desired cutoff distance. Thus, studying the conformations and interactions of beta amyloid protein and GM1 gives a starting point to investigate the so called 'GAβ42' in the membrane.