At what temperature can enzymes maintain their catalytic activity?

Area of Science:

• Biochemistry
• Enzyme kinetics
• Protein chemistry

Background:

• Proteins contain tightly bound water molecules essential for their structure and function.
• Understanding the thermal stability of proteins and enzymes is crucial for industrial applications.

Purpose of the Study:

• To determine the temperature required to remove tightly bound water from proteins.
• To assess the thermal stability of proteins and enzymes at elevated temperatures.
• To investigate the potential for enzyme activity at high temperatures.

Main Methods:

• Thermogravimetric analysis (TGA) and Karl Fischer titrations were used to quantify water removal.
• Electrophoresis and amino acid analysis were employed to evaluate protein and polypeptide integrity.
• Enzyme activity assays were performed on immobilised enzymes at elevated temperatures.

Main Results:

• Temperatures exceeding 200°C are necessary to eliminate tightly bound water from proteins.
• Heating proteins to these temperatures did not result in polypeptide chain cleavage or significant chemical degradation.
• Immobilised Candida antarctica lipase demonstrated sustained catalytic activity in transesterification at 130°C.

Conclusions:

• Proteins can withstand high temperatures (over 200°C) without structural or chemical damage, provided water is removed.
• Enzymes can be stabilized against thermal denaturation and retain activity at elevated temperatures.
• High-temperature biocatalysis is feasible using immobilised enzymes, opening new avenues for industrial processes.