title: Formation of a bioconjugate composed of hemin, smectite, and quaternary ammonium chloride that is soluble and active in hydrophobic media.
abstract: Hemin (Fe(3+)) was adsorbed onto synthetic smectite (clay mineral) intercalated with a quaternary alkenylammonium compound, dioleyldimethylammonium chloride (DOA), to form a hemin-smectite-DOA conjugate. The hemin-smectite-DOA conjugate was soluble in organic solvents such as benzene and toluene to form a transparent colloidal solution with a light yellow color. Its absorption spectrum in benzene showed two bands, 600 and 568 nm, in the visible region and a sharp Soret band at 400 nm with the molar extinction coefficient of 7.5 x 10(4) M(-1) cm(-1). The formation of the conjugate of smectite and DOA was confirmed by X-ray diffraction analysis: the basal spacing, d(001), of hemin-smectite-DOA conjugate was 19 A which is an expansion of the interlayer space by 5 A based upon the basal spacing of smectite of 14 A. Hemin-smectite-DOA conjugate catalyzed the peroxidase-like reaction in organic solvents using benzoyl peroxide as the hydrogen acceptor and leucocrystal violet as the hydrogen donor. The temperature-dependent peroxidase-like activity of the conjugate was compared with peroxidase activity of horseradish peroxidase. The hemin-smectite-DOA conjugate exhibited higher activity as the temperature was increased from 30 to 70 degrees C, while horseradish peroxidase activity was reduced as the temperature was increased.
authors.affiliation: Toin Human Science and Technology Center, Department of Biomedical Engineering, Toin University of Yokohama, Kurogane-cho, Aoba-ku, Yokohama 225-8502.
authors.forename: Masaru
authors.initials: M
authors.lastname: Kurosawa
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Itoh
authors.forename: Yoh
authors.initials: Y
authors.lastname: Kodera
authors.forename: Ayako
authors.initials: A
authors.lastname: Matsushima
authors.forename: Misao
authors.initials: M
authors.lastname: Hiroto
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nishimura
authors.forename: Yuji
authors.initials: Y
authors.lastname: Inada
mesh_terms: D001554:Benzene; D002384:Catalysis; D003102:Colloids / Q000737:chemistry; D005765:Gastrointestinal Agents / Q000737:chemistry*; D006427:Hemin / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D009829:Oleic Acids / Q000737:chemistry*; D010544:Peroxidases / Q000737:chemistry / Q000378:metabolism*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D017640:Silicates; D012995:Solubility; D013053:Spectrophotometry; D013696:Temperature; D013997:Time Factors; D014867:Water
chemical_list: D003102:Colloids; D005765:Gastrointestinal Agents; D009829:Oleic Acids; D000644:Quaternary Ammonium Compounds; D017640:Silicates; D014867:Water; D006427:Hemin; C033214:Smectite; D010544:Peroxidases; C459999:dioleyldimethylammonium chloride; D001554:Benzene