Figure 7.

Addition of Ni²⁺ induces aggregation distinct from fibril formation. Electron micrographs of negatively stained aggregates of Orb2A87 collected 6 hours after the start of an aggregation study. Orb2A87 without metal and in the presence of a 2.5 molar excess of Mg²⁺ show typical bundled amyloid fibrils. Aggregates that formed in the presence of a 2.5 molar excess of Ni²⁺ look rather amorphous although high Tht fluorescence was observed in this case. Scale bars: 200 nm.