Enhancing enzyme stability against TiO2-UV induced inactivation

Area of Science:

• Biochemistry
• Materials Science
• Photocatalysis

Background:

• Enzymes are crucial in many applications but are susceptible to photooxidation when used with inorganic photocatalysts like titanium dioxide (TiO2).
• Protecting enzymes from degradation under UV light exposure is essential for their effective and prolonged use in photocatalytic systems.

Purpose of the Study:

• To develop an enhanced stabilization strategy for enzymes against photooxidation induced by TiO2 under UV light.
• To investigate the efficacy of a novel enzyme conjugate incorporating UV-absorbing and free radical-scavenging moieties.

Main Methods:

• Conjugating chymotrypsin with an oligomeric adduct containing UV-absorbing 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate (HBMA) and free radical-absorbing 2-methacryloyloxyethyl-6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylate (Trolox-HEMA).
• Adsorbing the modified enzyme onto TiO2 and exposing it to UV light to assess stabilization against photooxidation.
• Comparing the deactivation rates of Trolox when conjugated separately versus integrated within the same chain.

Main Results:

• The novel conjugate significantly enhanced the stability of chymotrypsin against TiO2-UV induced photooxidation.
• Juxtaposing Trolox and HBMA within a single chain reduced Trolox deactivation by TiO2-UV, enabling localized protection.
• The modified enzyme, when adsorbed on TiO2, effectively absorbed UV light and free radicals, reducing photooxidation rates.

Conclusions:

• The developed conjugate provides effective stabilization for enzymes used with TiO2 photocatalysts under UV irradiation.
• This approach offers a promising strategy for enhancing enzyme longevity and performance in photocatalytic applications.
• The design of multifunctional conjugates is key to overcoming enzyme deactivation challenges in photooxidative environments.