Citation

Laszlo JA, Jackson M, Blanco RM. Journal of Molecular Catalysis B: Enzymatic 2011; 69(1-2): 60-65.

Copyright

(Copyright © 2011)

DOI

10.1016/j.molcatb.2010.12.011

PMID

unavailable

Abstract

Matrix morphology and surface polarity effects were investigated for Candida antarctica lipase B immobilization. Measurements were made of the amount of lipase immobilized and the catalyst's tributyrin hydrolysis activity, along with a determination of the lipase's functional fraction by active-site titration. Soluble, purified lipase had an active fraction of 84%. Immobilization on the hydrophobic surface of macroporous poly(methylmethacrylate) resin resulted in the full retention the lipase active fraction, while immobilization on the hydrophobic surface of mesoporous, amorphous, octyl-modified silica allowed retention of just half of the lipase active fraction. The polar surface of unmodified mesoporous, amorphous silica bound the lipase in such a manner that all of the immobilized enzyme was active. Mesoporous, crystalline SBA-15 silica also bound lipase so that it all was active. The polar, non-porous surface of fumed silica retained only a small fraction (28%) of active lipase. Substantial differences were found among the various supports in their ability to preserve catalytic activity upon vacuum drying. These findings demonstrate that surface polarity alone is not the only determinant for immobilization, as hydrophobic poly(methylmethacrylate) and hydrophilic SBA-15 were equally competent as lipase supports. The ordered-channel mesostructure of SBA-15 may provide a critical balance of interactions with the enzyme to preserve its native conformation. © 2010 Elsevier B.V.

Language: en

Keywords

article; unclassified drug; Silica; nonhuman; enzyme activity; enzyme immobilization; Suicide inhibitor; Enzyme immobilization; Enzymes; Surface chemistry; titrimetry; surface property; Yeast; enzyme purification; Isomers; silicon dioxide; Catalytic activity; Catalyst activity; hydrophobicity; Titration; poly(methyl methacrylate); Immobilized enzyme; Hydrophobicity; Active fraction; Amorphous silica; Candida; Candida antarctica; Candida antarctica lipase B; fractionation; fumed silica; Fumed silicas; Hydrolysis activity; Hydrophobic surfaces; lipase B; Macroporous; matrix; Mesoporous; Mesoporous materials; Mesostructures; Modified silica; ms 3030 silica; Native conformation; octyl silica; Polar surfaces; Porous surface; Resins; sba 15 silica; SBA-15 silica; Specific activity; Surface influences; Surface morphology; Surface polarities; Titration analysis; tributyrin; Tributyrin; Vacuum drying