Enhancement in thermal stability and resistance to denaturants of lipase encapsulated in mesoporous silica with alkyltrimethylammonium (CTAB).
We assembled a highly durable conjugate with both a high-density accumulation and a regular array of lipase, by encapsulating it in mesoporous silica (FSM) with alkyltrimethylammonium (CTAB) chains on the surface. The activity for hydrolyzing esters of the lipase immobilized in mesoporous silica was linearly related to the concentration of lipase, whereas that of non-immobilized lipase showed saturation due to self-aggregation at a high concentration. The lipase conjugate also had increased resistance to heating when stayed in the silica coupling with CTAB. In addition, encapsulating the enzyme with FSM coupled CTAB caused the lipase to remain stable even in the presence of urea and trypsin, suggesting that the encapsulation prevented dissociation and denaturing. This conjugate had much higher activity and much higher stability for hydrolyzing esters when compared to the native lipase. These results show that FSM provides suitable support for the immobilization and dispersion of proteins in mesopores with disintegration of the aggregates.
National Institute of Advanced Industrial Science and Technology (AIST), Nigatake 4-2-1, Miyagino-ku, Sendai 983-8551, Japan. t-itoh@ni.aist.go.jp
Tetsuji
T
Itoh
Ryo
R
Ishii
Shun-ichi
S
Matsuura
Junko
J
Mizuguchi
Satoshi
S
Hamakawa
Taka-aki
TA
Hanaoka
Tatsuo
T
Tsunoda
Fujio
F
Mizukami
D000327:Adsorption / Q000187:drug effects; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000378:metabolism*; D004795:Enzyme Stability / Q000187:drug effects; D008049:Lipase / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D016062:Porosity / Q000187:drug effects; D011489:Protein Denaturation / Q000187:drug effects*; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D012822:Silicon Dioxide / Q000378:metabolism*; D013696:Temperature; D014357:Trypsin / Q000494:pharmacology*; D014508:Urea / Q000494:pharmacology*
D002593:Cetrimonium Compounds; D012822:Silicon Dioxide; D014508:Urea; D008049:Lipase; D014357:Trypsin; D009584:Nitrogen; D000077286:Cetrimonium