A Nanoenzyme Constructed from Manganese and Strandberg-Type Phosphomolybdate with Versatility in Antioxidant and Modulating Conformation of Aß Protein Misfolding Aggregates In Vitro.

Amyloid ß-peptide (Aß) misfolding aggregates with ß-sheet structures and surplus reactive oxygen species (ROS) are both considered to be the culprit of neuronal toxicity in Alzheimer's disease (AD). Therefore, modulating the misfolding mode of Aß and inhibiting ROS simultaneous has become an important method for anti-AD. Herein, a nanoscale manganese-substituted polyphosphomolybdate (H2en)3[Mn(H2O)4][Mn(H2O)3]2[P2Mo5O23]2·14.5H2O (abbreviated as MnPM) (en = ethanediamine) was designed and synthesized by single crystal to single crystal transformation method. MnPM can modulate the ß-sheet rich conformation of Aß aggregates, and thus reduce the formation of toxic species. Moreover, MnPM also possesses the ability to eliminate the free radicals produced by Cu2+-Aß aggregates. It can inhibit the cytotoxicity of ß-sheet-rich species and protect synapses of PC12 cells. MnPM combines the conformation modulating ability of Aß and anti-oxidation ability, which makes a promising multi-funcational molecular with a composite mechanism for the new conceptual designing in treatment of such protein-misfolding diseases.