Comparison of the reaction of methylglyoxal (MGO) with murine and human amyloid beta (Aß): Insights into a mechanism of Alzheimer's disease (AD).

Reacted with methylglyoxal (MGO), murine Aß(1-40) (mAß) produced significantly less superoxide anion (O2•-) compared to human Aß(1-40) (hAß). The reactions of MGO with mAß(R13H), hAß(H13F), Nα-acetyl-l-lysine, and Nα-acetyl-l-arginine implied that the lack of His13 in mAß prohibits its Lys16 residue from reacting to produce cross-linked reaction products and O2•-. Our results suggest that murine brains are under less oxidative stress than human brains, which may be one of the reasons why rodents do not develop AD-like symptoms, and which provides further insight into a chemical mechanism for the development of AD in humans.