NMR solution structure of rat Abeta(1-16): toward understanding the mechanism of rats' resistance to Alzheimer's disease.
Istrate, A.N., Tsvetkov, P.O., Mantsyzov, A.B., Kulikova, A.A., Kozin, S.A., Makarov, A.A., Polshakov, V.I.(2012) Biophys J 102: 136-143
- PubMed: 22225807 
- DOI: https://doi.org/10.1016/j.bpj.2011.11.4006
- Primary Citation of Related Structures:  
2LI9 - PubMed Abstract: 
In an attempt to reveal the mechanism of rats' resistance to Alzheimer's disease, we determined the structure of the metal-binding domain 1-16 of rat β-amyloid (rat Aβ(1-16)) in solution in the absence and presence of zinc ions. A zinc-induced dimerization of the domain was detected. The zinc coordination site was found to involve residues His-6 and His-14 of both peptide chains. We used experimental restraints obtained from analyses of NMR and isothermal titration calorimetry data to perform structure calculations. The calculations employed an explicit water environment and a simulated annealing molecular-dynamics protocol followed by quantum-mechanical/molecular-mechanical optimization. We found that the C-tails of the two polypeptide chains of the rat Aβ(1-16) dimer are oriented in opposite directions to each other, which hinders the assembly of rat Aβ dimers into oligomeric aggregates. Thus, the differences in the structure of zinc-binding sites of human and rat Aβ(1-16), their ability to form regular cross-monomer bonds, and the orientation of their hydrophobic C-tails could be responsible for the resistance of rats to Alzheimer's disease.
Organizational Affiliation: 
Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia.