title: Polar organic solvent added to an aqueous solution changes hydrolytic property of lipase.
abstract: For developing further uses of lipase as a biocatalyst, its hydrolytic activity toward some esters was investigated in a miscible solution composed of a buffer and a polar organic solvent. Twenty percent dimethylformamide, 35% dimethylsulfoxide, 15% 1,4-dioxane, 15% dimethoxyethane, and 2% diethoxyethane promoted the hydrolysis by a lipase from Rhizomucor miehei toward some hydrophobic substrates, 4-methylumbelliferyl oleate, 4-methylumbelliferyl palmitate, and monoolein. While hydrolysis by this lipase toward the substrates with a relatively weak hydrophobicity (4-metylumbelliferyl heptanoate and 4-methylumbelliferyl nanoate) was suppressed by these solvents. A fluorometric analysis showed that the polar organic solvent in the buffer induced some conformational change around a tryptophan residue of R. miehei lipase. In addition to the influence of the miscible solvent on the solubility of the substrates, the conformational change of the protein induced by the miscible solvent would also affect the reactive properties of the lipase. Adding a polar organic solvent to an aqueous solution will be an efficient method for changing hydrolytic performance of lipases.
authors.affiliation: National Food Research Institute, Kannondai 2-1-12, Tsukuba, Ibaraki 305-8642, Japan. wakako@nfri.affrc.go.jp
authors.forename: Wakako
authors.initials: W
authors.lastname: Tsuzuki
authors.forename: Akemi
authors.initials: A
authors.lastname: Ue
authors.forename: Akihiko
authors.initials: A
authors.lastname: Nagao
mesh_terms: D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004126:Dimethylformamide / Q000494:pharmacology; D004146:Dioxanes / Q000494:pharmacology; D005019:Ethyl Ethers / Q000494:pharmacology; D005026:Ethylene Glycols / Q000494:pharmacology; D006868:Hydrolysis; D057927:Hydrophobic and Hydrophilic Interactions; D006923:Hymecromone / Q000031:analogs & derivatives / Q000378:metabolism; D007700:Kinetics; D008049:Lipase / Q000737:chemistry* / Q000378:metabolism*; D009930:Organic Chemicals / Q000737:chemistry* / Q000494:pharmacology; D020103:Rhizomucor / Q000201:enzymology; D012997:Solvents; D013050:Spectrometry, Fluorescence
chemical_list: D004146:Dioxanes; D005019:Ethyl Ethers; D005026:Ethylene Glycols; D009930:Organic Chemicals; D012997:Solvents; D006923:Hymecromone; C077455:ethylene glycol diethyl ether; D004126:Dimethylformamide; D008049:Lipase; C024683:1,2-dimethoxyethane; C025223:1,4-dioxane; D004121:Dimethyl Sulfoxide