Structural evolution and stability of sol-gel biocatalysts
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Date
2005-11-27
Journal Title
Journal ISSN
Volume Title
Publisher
The Bragg Institute, Australian Nuclear Science and Technology Organisation
Abstract
Immobilisation strategies for catalytic enzymes are important as they allow reuse of the biocatalysts. Sol-gel materials have been used to immobilise Candida antarctica lipase B (CALB), a commonly used industrial enzyme with a known crystal structure. The sol-gel bioencapsulate is produced through the condensation of suitable metal alkoxides in the presence of CALB, yielding materials with controlled pore sizes, volume and surface chemistry. Sol-gel matrices have been shown to prolong the catalytic life and enhance the activity of CALB, although the molecular basis for this effect has yet to be elucidated due to the limitations of analysis techniques applied to date. Small angle neutron scattering (SANS) allows such multicomponent systems to be characterised through contrast matching. In the sol-gel bioencapsulate system, at the contrast match point for silica, residual scattering intensity is due to the CALB and density fluctuations in the matrix. A SANS contrast variation series found the match point for the silica matrix, both with and without enzyme present, to be around 35 percent. The model presented here proposes a mechanism for the interaction between CALB and the surrounding sol-gel matrix, and the observed improvement in enzyme activity and matrix strength. The SANS protocol developed here may be applied more generally to bioencapsulates. © The Authors
Description
Physical copy held by ANSTO Library at DDC 539.7217/2
Keywords
Chemistry, Complexes, Enzymes, Esterases, Fungi, Microorganisms, Microstructure, Minerals, Organic compounds, Physical properties, Plants, Proteins, Scattering, Variations
Citation
Rodgers, L. E., Holden, P, J., Knott, R. B., Foster, L. J. R., & Bartlett, J. R. (2005). Structural evolution and stability of sol-gel biocatalysts. Paper presented at the Eighth International Conference on Neutron Scattering ICNS 2005: "Neutrons for structure and dynamics - a new era", Sydney Convention & Exhibition Centre, Sydney, Australia, 27 November-2 December 2005. In Final Programme and Abstract Book, (pp. 128).