title: AOT/isooctane reverse micelles with a microaqueous core act as protective shells for enhancing the thermal stability of Chromobacterium viscosum lipase.
abstract: According to the different environmental systems for lipase reactions, changes in thermal stability were investigated by employing the Chromobacterium viscosum lipase and a two-step series-type deactivation model. The half-life (6.81 h) of the lipase entrapped in reverse micelles at 70 °C was 9.87- and 14.80-fold longer than that in glycerol pool or in aqueous buffer. The deactivation constants for the first and second step (k1 and k2) at all temperatures drastically decreased when the lipase was entrapped in reverse micelles. In particular, k1 (3.84 h(-1)) at 70 °C in reverse micelles was 1.57-fold lower than that in aqueous buffer (6.03 h(-1)). Based on the fluorescence spectrometry, the amount of excited forms of tryptophan and tyrosine increased markedly during the thermal-treatment in aqueous buffer, whereas no significant fluctuation was noted in the reversed micellar system. These results indicated that the encapsulation in reverse micelles could be favorable for preventing the enzyme from heat-induced denaturation.
authors.affiliation: Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea.
authors.forename: Sung-Chul
authors.initials: SC
authors.lastname: Hong
authors.affiliation: Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea.
authors.forename: Kyung-Min
authors.initials: KM
authors.lastname: Park
authors.affiliation: Department of Rural Systems Engineering, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Young-Hwan
authors.initials: YH
authors.lastname: Son
authors.affiliation: Institute of Advanced Machinery and Design, School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Ho-Sup
authors.initials: HS
authors.lastname: Jung
authors.affiliation: Institute of Advanced Machinery and Design, School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Keesung
authors.initials: K
authors.lastname: Kim
authors.affiliation: Department of Food Science and Technology, Seoul National University of Science and Technology, Seoul 139-743, Republic of Korea.
authors.forename: Seung Jun
authors.initials: SJ
authors.lastname: Choi
authors.affiliation: Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea; Center for Food and Bioconvergence, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-742, Republic of Korea. Electronic address: pschang@snu.ac.kr.
authors.forename: Pahn-Shick
authors.initials: PS
authors.lastname: Chang
mesh_terms: D008049:Lipase / Q000737:chemistry*; D008823:Micelles; D013050:Spectrometry, Fluorescence; D014867:Water / Q000737:chemistry*
chemical_list: D008823:Micelles; D014867:Water; D008049:Lipase; C454481:lipase, Chromobacterium viscosum
keywords: Chromobacterium viscosum lipase; Deactivation kinetics; Reverse micelles; Thermal stability