Protein Aggregation Kinetics

Kinetic Parameters

kn (nucleation rate) 0.001 ke (elongation rate) 0.5 koff (depolymerization) 0.05 Seed fraction 0.0 Total monomer M₀ 1.0

Observables

Free monomer m—

Aggregated fraction—

# fibrils N—

Lag time τ—

Time0

About

Protein aggregation (e.g., amyloid-β, α-synuclein) follows nucleation-elongation kinetics. Monomers slowly form nuclei (rate kn), which then grow rapidly (rate ke). This produces a characteristic sigmoidal curve with a lag phase, exponential growth, and plateau. Adding preformed seeds (seeded nucleation) eliminates the lag phase. Relevant to Alzheimer's, Parkinson's disease.