title: Alkyl-substituted methoxysilanes enhance the activity and stability of D-amino acid oxidase encapsulated in biomimetic silica.
abstract: Several alkyl-substituted methoxysilanes were evaluated as potential activity and stability enhancing agents for biomimetic silicification of Rhodosporidium toruloides D-amino acid oxidase (RtDAO). When methyl-substituted silanes along with tetramethoxysilane were used as silicic acid precursors for polyallylamine (PAA)--or R5 peptide-catalyzed silicic encapsulation, the RtDAO activity increased with the degree of substitution and the molar ratio up to 15 % of methyl-substituted silanes added. In the presence of 15 mol% trimethylmethoxysilane, the specific activities of encapsulated RtDAO catalyzed by PAA and R5 increased by 1.4- and 4.8-fold, respectively. For PAA-catalyzed encapsulation, a 2.4-fold increase occurred with 30 mol% n-propyltrimethoxysilane; this modification increased the T (m) value by 10 °C and gave a threefold longer half-life in the presence of 10 mM H(2)O(2) as compared to the encapsulation using tetramethoxysilane only.
authors.affiliation: Department of Bioengineering, Tatung University, 40 Chungshan N. Rd. Sec. 3, Taipei, 10452, Taiwan. iching@ttu.edu.tw
authors.forename: I-Ching
authors.initials: IC
authors.lastname: Kuan
authors.forename: Chiao-An
authors.initials: CA
authors.lastname: Chuang
authors.forename: Shiow-Ling
authors.initials: SL
authors.lastname: Lee
authors.forename: Chi-Yang
authors.initials: CY
authors.lastname: Yu
mesh_terms: D001487:Basidiomycota / Q000201:enzymology; D040761:Biomimetic Materials / Q000737:chemistry*; D003605:D-Amino-Acid Oxidase / Q000737:chemistry* / Q000378:metabolism*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism; D006861:Hydrogen Peroxide; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012821:Silanes / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013379:Substrate Specificity
chemical_list: D004800:Enzymes, Immobilized; D005656:Fungal Proteins; D011994:Recombinant Proteins; D012821:Silanes; C492568:propyltrimethoxysilane; D012822:Silicon Dioxide; D006861:Hydrogen Peroxide; D003605:D-Amino-Acid Oxidase