Abstract
Single enzyme nanoparticles of α-chymotrypsin (SEN-CT), in which each CT molecule is surrounded by a thin polymeric organic/inorganic network, stabilized the CT activity in a shaking condition as well as in a non-shaking condition. Since SEN-CT is soluble in a buffer solution and less than 10 nm in size, SEN-CT could be further immobilized in nanoporous silica with an average pore size of 29 nm. Free CT and SEN-CT were immobilized in nanoporous silica (NPS), and nanoporous silica that was first silanized with aminopropyltriethoxysilane (amino-NPS) to generate a positive surface charge. The SEN-CT adsorbed in amino-NPS was more stable than CT immobilized by either adsorption in NPS or covalent bonding to amino-NPS. In shaking conditions, nanoporous silica provided an additional stabilization by protecting SEN-CT from shear stresses. At 22 °C with harsh shaking, free, NPS-adsorbed and NPS-covalently attached CT showed half lives of 1, 62, and 80 h, respectively; whereas SEN-CT adsorbed in amino-NPS showed no activity loss within 12 days. The combination of SENs and nanoporous silica, which makes an active and stable immobilized enzyme system, represents a new structure for biocatalytic applications.
Original language | English |
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Pages (from-to) | 474-480 |
Number of pages | 7 |
Journal | Enzyme and Microbial Technology |
Volume | 39 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2006 Jul 3 |
Externally published | Yes |
Keywords
- Enzyme immobilization
- Enzyme stabilization
- Mesocellular foams
- Nanoporous silica
- Single enzyme nanoparticles
- α-Chymotrypsin
ASJC Scopus subject areas
- Biotechnology
- Bioengineering
- Biochemistry
- Applied Microbiology and Biotechnology