Linear correlation between thermal stability and folding kinetics of lysozyme

Area of Science:

• Biochemistry
• Protein Folding Dynamics
• Biophysical Chemistry

Background:

• Hen egg white lysozyme is a model protein for studying folding.
• Understanding protein stability and refolding mechanisms is crucial in biochemistry.
• Protein denaturation and refolding are influenced by environmental factors like pH.

Purpose of the Study:

• To investigate the refolding and thermal denaturation of hen egg white lysozyme.
• To explore the impact of a wide pH range (1.5–9.4) on lysozyme stability and folding kinetics.
• To determine any correlation between thermal denaturation parameters and refolding rates.

Main Methods:

• Stopped-flow circular dichroism (CD) spectroscopy to monitor protein structure changes during refolding.
• Differential scanning calorimetry (DSC) to measure thermal denaturation profiles and determine melting temperatures (T(m)).
• Kinetic analysis of the slow folding phase to obtain refolding rates (lnk(2)).

Main Results:

• Hen egg white lysozyme exhibits distinct refolding and thermal denaturation behaviors across a broad pH spectrum.
• A significant linear correlation was identified between the thermal denaturation temperature (T(m)) and the logarithm of the refolding rate constant (lnk(2)) for the slow folding phase.
• These findings suggest an interconnectedness between the thermodynamic stability and kinetic aspects of lysozyme folding.

Conclusions:

• The study establishes a quantitative relationship between the stability and folding kinetics of hen egg white lysozyme.
• The observed linear correlation provides insights into the underlying mechanisms governing protein refolding and stability.
• This research contributes to a deeper understanding of protein biophysics and folding pathways.