Visualizing Amyloid Assembly

Specific precursor states formed from soluble native proteins have been identified as leading to oligomerization and amyloid formation. Ordered amyloid fibril protein aggregates are a hallmark of a class of human diseases that includes Parkinson's and Alzheimer's. How proteins assemble into these structures is poorly understood (1) but is thought to play a direct role in disease. Two recent studies provide key insights into this problem. On page 362 of this issue, Neudecker et al. (2) have visualized the changes that convert a normally soluble protein into an aggregation-prone amyloid precursor. Laganowski et al. (3) have described the structure of a subsequent oligomeric amyloid intermediate of the kind currently believed to be responsible for amyloid-associated toxicity (4).