Protein Aggregation — Nucleation & Seeding

Amyloid kinetics: lag phase → exponential growth → saturation

Aggregated: 0% | Fibrils: 0
Amyloid fibril formation follows nucleated polymerization: a slow, thermodynamically unfavorable nucleation step creates seeds that then grow rapidly. Secondary nucleation (fibril fragmentation creating new seeds) produces an autocatalytic positive feedback, generating the characteristic sigmoidal kinetics seen in diseases like Alzheimer's and Parkinson's.