Non-Arrhenius Reaction-Diffusion Kinetics for Protein Inactivation over a Large Temperature Range

Area of Science:

• Biophysics
• Biochemistry
• Physical Chemistry

Background:

• Protein folding and unfolding are critical for biological function.
• Current experimental and simulation methods are limited in studying protein unfolding across broad temperature ranges.
• Understanding irreversible protein inactivation kinetics at extreme temperatures remains a challenge.

Purpose of the Study:

• To investigate protein inactivation kinetics at extremely high temperatures using precise localized heating.
• To develop a model that accurately describes protein inactivation across physiological to extreme temperatures.
• To provide guidelines for optimizing protein photoinactivation and applications like molecular hyperthermia.

Main Methods:

• Utilized nanosecond pulsed heating of individual plasmonic nanoparticles for localized, precise heating.
• Measured protein inactivation kinetics at both low and extremely high temperatures.
• Developed and analyzed a reaction-diffusion model incorporating a diffusion limit.

Main Results:

• Observed that protein unfolding kinetics become less temperature-sensitive at higher temperatures, deviating from Arrhenius behavior.
• The proposed reaction-diffusion model successfully accounts for this observed temperature dependence.
• Identified distinct regimes of protein inactivation: reaction-limited, transition, and diffusion-limited.

Conclusions:

• The reaction-diffusion model provides a comprehensive framework for understanding protein inactivation kinetics over a vast temperature range.
• This model is valuable for designing optimal conditions for protein photoinactivation and related applications.
• The findings advance the understanding of protein inactivation and have implications for molecular hyperthermia and future protein studies.