Thermal Inactivation, Denaturation and Aggregation Processes of Papain-Like Proteases

Area of Science:

• Biochemistry
• Enzymology
• Protein Chemistry

Background:

• Industrial processes like medicine and cosmetic production often involve high-temperature sterilization.
• Understanding the thermal behavior of enzymes is critical for process optimization and product quality.
• Papain-like proteases (ficin, bromelain, papain) are widely used and sensitive to heat.

Purpose of the Study:

• To investigate the thermal inactivation, aggregation, and denaturation of ficin, bromelain, and papain.
• To identify critical temperatures for these enzymes during thermal processing.
• To provide insights for technological regulation in industries utilizing these proteases.

Main Methods:

• Enzyme kinetics using BAPNA substrate to quantify protease inactivation.
• Differential Scanning Calorimetry (DSC) to assess thermal denaturation.
• Dynamic Light Scattering (DLS) and spectrophotometry (280 nm) to evaluate protein aggregation.

Main Results:

• Ficin and papain inactivation followed a single decay step with subsequent stabilization.
• Bromelain exhibited a two-step inactivation process with distinct kinetics.
• Protein aggregation accompanied denaturation, with similar denaturation rates and molecular sizes for active and inactive enzyme forms.

Conclusions:

• Enzyme stabilization can preserve residual activity after thermal inactivation.
• The distinct thermal inactivation profiles of ficin, papain, and bromelain necessitate tailored process controls.
• Understanding these thermal behaviors is vital for maintaining enzyme functionality in industrial applications.