Possible role of amyloid-beta, adenine nucleotide translocase and cyclophilin-D interaction in mitochondrial dysfunction of Alzheimer's disease

Alzheimer's disease (AD) is a common neurodegenerative disease characterized by both extra- as well as intracellular deposition of amyloid beta peptides (Abeta). The accumulation of Abeta in mitochondria is associated with mitochondrial dysfunction and oxidative stress in AD. Recent evidences suggest the involvement of Abeta interaction with mitochondrial proteins such as cyclophilin-D (CypD) in oxidative stress, mitochondrial permeability transition (MPT) and Alzheimer's associated neurodegeneration. The present study is an effort to elucidate the molecular interaction of Abeta with other proteins involved in MPT like adenine nucleotide translocase (ANT). Based on our prediction for sub-cellular localization using WolfPSORT and other experimental evidences, we suggest that Abeta molecules localize in mitochondrial inner membrane in close vicinity with ANT. Our simulation study for protein-protein interaction clearly suggests that the ANT-Abeta interaction is stronger than CypD-Abeta interaction. Further the lipophilic nature and evidences regarding the localization of Abeta in the mitochondrial inner-membrane also support the possibility of strong interaction between ANT and Abeta. Interaction between ANT and Abeta may affect normal physiological function of ANT i.e. transport of ATP and ADP. Since both the CypD-Abeta as well as ANT-Abeta interaction are energetically favorable and both CypD and ANT are associated with the regulation of MPT, the functional impact of both these interactions warrants more in-depth investigations for elucidating the mechanisms involved in Abeta-induced oxidative stress.