title: Solubilization of enzymes in water-in-oil microemulsions and their rapid and efficient release through use of a pH-degradable surfactant.
abstract: alpha-Chymotrypsin and lysozyme were solubilized in a water/O-[(2-tridecyl, 2-ethyl-1,3-dioxolan-4-yl)methoxy]-O'-methoxy poly(ethylene glycol) (CK-2,13 surfactant)/isooctane water-in-oil microemulsion solution at 1.5-2 and 10 g l(-1) for 0.15 and 1.2 M: CK-2,13, respectively. Upon contact with an equal volume of 0.1 M: NaH(2)PO(4)/Na(2)HPO(4) buffer, pH 5, a three-phase system (Winsor-III system) was formed, consisting of a surfactant-rich middle phase and aqueous and isooctane-rich "excess" phases. Both enzymes were rapidly released into the aqueous excess phase, with 70% recovery of each in 30 and 60 min for microemulsion solutions containing 0.15 and 1.2 M: surfactant, respectively. The recovered enzymes retained >90% of their original specific activity.
authors.affiliation: Department of Chemistry, University of Alabama in Huntsville, Huntsville, AL 35899, USA.
authors.forename: Maithili E
authors.initials: ME
authors.lastname: Rairkar
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Hayes
authors.forename: J Milton
authors.initials: JM
authors.lastname: Harris
mesh_terms: D000818:Animals; D002417:Cattle; D002645:Chickens; D002918:Chymotrypsin / Q000378:metabolism*; D004655:Emulsions; D006863:Hydrogen-Ion Concentration; D009113:Muramidase / Q000378:metabolism*; D009821:Oils / Q000378:metabolism*; D012995:Solubility; D012996:Solutions; D013501:Surface-Active Agents / Q000378:metabolism*; D014867:Water / Q000378:metabolism*
chemical_list: D004655:Emulsions; D009821:Oils; D012996:Solutions; D013501:Surface-Active Agents; D014867:Water; D009113:Muramidase; D002918:Chymotrypsin