Insight into the correlation between lag time and aggregation rate in the kinetics of protein aggregation

TL;DR

This paper investigates the relationship between lag time and aggregation rate in protein aggregation, revealing that their product depends on a kinetic index that is consistent across different conditions, providing new insights into aggregation kinetics.

Contribution

It introduces a novel correlation between lag time and aggregation rate based on a kinetic index, linking experimental observations with theoretical models.

Findings

The product of lag time and aggregation rate depends on a single kinetic index.

The kinetic index is relatively invariant across different experimental conditions.

The study connects the kinetic index to a fundamental kinetic parameter in protein aggregation theory.

Abstract

Under favourable conditions, many proteins can assemble into macroscopically large aggregate's, Parkinson's and other neurological and systemic diseases. The overall process of protein aggregation is characterized by initial lag time during which no detectable aggregation occurs in the solution and by maximal aggregation rate at which the dissolved protein converts into aggregates. In this study, the correlation between the lag time and the maximal rate of protein aggregation is analyzed. It is found that the product of these two quantities depends on a single numerical parameter, the kinetic index of the curve quantifying the time evolution of the fraction of protein aggregated. As this index depends relatively little on the conditions and/or system studied, our finding provides insight into why for many experiments the values of the product of the lag time and the maximal aggregation rate are often equal or quite close to each other. It is shown how the kinetic index is related to a basic kinetic parameter of a recently proposed theory of protein aggregation.