Title
Co-Immobilization of Superoxide Dismutase with Catalase on Soft Microparticles Formed by Self-Assembly of Amphiphilic Poly(Aspartic Acid)
Author
Siyu Mao, Rong Li, Wenchen Wang, Wei Feng, Peijun Ji
Year
2017
Journal
Catalysts
Abstract
Through genetic engineering technology, catalase (CAT) and superoxide dismutase (SOD) have been separately fused to an elastin-like polypeptide (ELP). Thus, the enzymes can be purified through phase transition. Hexadecylamine-modified poly(aspartic acid) (HPASP) is able to self-assemble, forming soft microparticles. The HPASP microparticles were used to co-immobilize SOD-ELP and CAT-ELP through amidation reaction. Circular dichroism (CD) confirmed that the secondary structures of the co-immobilized enzymes have been preserved. Fluorescence spectra showed that the co-immobilized enzymes exhibited a higher stability than the free enzymes. Dismutation of superoxide by superoxide dismutase (SOD) generates hydrogen peroxide. By using the co-immobilized enzymes (SOD-ELP/CAT-ELP@HPASP), the generated hydrogen peroxide of SOD-ELP can be decomposed in situ by CAT-ELP. Activity assay results demonstrated that the superoxide anion (•O2−) scavenging ability is 63.15 ± 0.75% for SOD-ELP/CAT-ELP@HPASP. The advantages of the approach of enzyme co-immobilization include the fact that the soft support HPASP itself is a polypeptide in nature, the stability of immobilized enzymes is improved, and a high activity has been achieved. Potentially SOD-ELP/CAT-ELP@HPASP can be applied in the cosmetic industry.
Full Article
Instrument
J-810
Keywords
Circular dichroism, Secondary structure, Biochemistry