title: Effect of organic solvents on the activity and stability of an extracellular protease secreted by the haloalkaliphilic archaeon Natrialba magadii.
abstract: The effect of various organic solvents on the activity and stability of an extracellular protease produced by the haloalkaliphilic archaeon Natrialba magadii was tested. This protease was active and stable in aqueous-organic solvent mixtures containing 1.5 M NaCl and glycerol, dimethylsulfoxide (DMSO), N,N-dimethyl formamide, propylenglycol, and dioxane. Among the solvents tested, DMSO, propylenglycol, and glycerol were effective in preserving enzyme stability in suboptimal NaCl concentrations. The stabilizing effect of DMSO on this haloalkaliphilic protease was more efficient at pH 8 than at pH 10, suggesting that DMSO may not substitute for salt to allow halophilic proteins to withstand the effect of high pH values. These results show that Nab. magadii extracellular protease is a solvent tolerant enzyme and suggest a potential application of this haloalkaliphilic protease in aqueous-organic solvent biocatalysis.
authors.affiliation: Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, CC 1245, Mar del Plata, 7600, Argentina.
authors.forename: Diego M
authors.initials: DM
authors.lastname: Ruiz
authors.forename: Rosana E
authors.initials: RE
authors.lastname: De Castro
mesh_terms: D019843:Archaeal Proteins / Q000187:drug effects / Q000378:metabolism; D001709:Biotechnology / Q000379:methods; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004146:Dioxanes / Q000494:pharmacology; D004795:Enzyme Stability / Q000187:drug effects; D006216:Halobacteriaceae / Q000187:drug effects / Q000201:enzymology*; D009930:Organic Chemicals / Q000494:pharmacology*; D010447:Peptide Hydrolases / Q000187:drug effects* / Q000378:metabolism; D019946:Propylene Glycol / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology*; D012997:Solvents / Q000494:pharmacology*
chemical_list: D019843:Archaeal Proteins; D004146:Dioxanes; D009930:Organic Chemicals; D012997:Solvents; D012965:Sodium Chloride; D019946:Propylene Glycol; D010447:Peptide Hydrolases; C025223:1,4-dioxane; D004121:Dimethyl Sulfoxide