TY - JOUR
T1 - Enzyme stabilization by covalent binding in nanoporous sol-gel glass for nonaqueous biocatalysis
AU - Wang, Ping
AU - Dai, Sheng
AU - Waezsada, S. D.
AU - Tsao, Alice Y.
AU - Davison, Brian H.
PY - 2001/8/6
Y1 - 2001/8/6
N2 - A unique nanoporous sol-gel glass possessing a highly ordered porous structure (with a pore size of 153 Å in diameter) was examined for use as a support material for enzyme immobilization. A model enzyme, α-chymotrypsin, was efficiently bound onto the glass via a bifunctional ligand, trimethoxysilylpropanal, with an active enzyme loading of 0.54 wt%. The glass-bound chymotrypsin exhibited greatly enhanced stability both in aqueous solution and organic solvents. The half-life of the glass-bound α-chymotrypsin was <1000-fold higher than that of-the native enzyme, as measured either in aqueous buffer or anhydrous methanol. The enhanced stability in methanol, which excludes the possibility of enzyme autolysis, particularly reflected that the covalent binding provides effective protection against enzyme inactivation caused by structural denaturation. In addition, the activity of the immobilized α-chymotrypsin was also much higher than that of the native enzyme in various organic solvents. From these results, it appears that the glass-enzyme complex developed in the present work can be used as a high-performance biocatalyst for various chemical processing applications, particularly in organic media.
AB - A unique nanoporous sol-gel glass possessing a highly ordered porous structure (with a pore size of 153 Å in diameter) was examined for use as a support material for enzyme immobilization. A model enzyme, α-chymotrypsin, was efficiently bound onto the glass via a bifunctional ligand, trimethoxysilylpropanal, with an active enzyme loading of 0.54 wt%. The glass-bound chymotrypsin exhibited greatly enhanced stability both in aqueous solution and organic solvents. The half-life of the glass-bound α-chymotrypsin was <1000-fold higher than that of-the native enzyme, as measured either in aqueous buffer or anhydrous methanol. The enhanced stability in methanol, which excludes the possibility of enzyme autolysis, particularly reflected that the covalent binding provides effective protection against enzyme inactivation caused by structural denaturation. In addition, the activity of the immobilized α-chymotrypsin was also much higher than that of the native enzyme in various organic solvents. From these results, it appears that the glass-enzyme complex developed in the present work can be used as a high-performance biocatalyst for various chemical processing applications, particularly in organic media.
KW - Enzyme immobilization
KW - Nonaqueous biocatalysis
KW - Organic solvents
KW - Sol-gel silica glass
KW - α-chymotrypsin
UR - http://www.scopus.com/inward/record.url?scp=0035817408&partnerID=8YFLogxK
U2 - 10.1002/bit.1114
DO - 10.1002/bit.1114
M3 - Article
C2 - 11400098
AN - SCOPUS:0035817408
SN - 0006-3592
VL - 74
SP - 249
EP - 255
JO - Biotechnology and Bioengineering
JF - Biotechnology and Bioengineering
IS - 3
ER -