Preparation and characterization of silk fibroin powder and its application to enzyme immobilization
Article first published online: 10 MAR 2003
Copyright © 1990 John Wiley & Sons, Inc.
Journal of Applied Polymer Science
Volume 40, Issue 1-2, pages 127–134, 5 - 20 July 1990
How to Cite
Yoshimizu, H. and Asakura, T. (1990), Preparation and characterization of silk fibroin powder and its application to enzyme immobilization. J. Appl. Polym. Sci., 40: 127–134. doi: 10.1002/app.1990.070400111
- Issue published online: 10 MAR 2003
- Article first published online: 10 MAR 2003
- Manuscript Accepted: 13 JUL 1989
- Manuscript Received: 25 APR 1989
The powders of Bombyx mori silk fibroin were prepared from aqueous solutions of silk fibroin by several kinds of the insolubilization methods, some of which used methanol. The insolubilization appeared to be effected by the conformational transition of silk fibroin from the random coil to antiparallel β-sheet form, which was monitored with IR spectroscopy. In order to characterize the structure of the power in the swollen state in water, a spin-labeled silk fibroin powder was prepared and the ESR spectra were observed, as well as 13C-NMR. The heterogeneous structure was analyzed quantitatively in terms of the fraction of fast, slow, and very slow components in the ESR spectra. Finally, an enzyme, invertase, was immobilized with the silk fibroin powder. The thermal stability of the enzyme was much improved by the immobilization.