title: Encapsulation of myoglobin with a mesoporous silicate results in new capabilities.
abstract: A metmyoglobin (Fe3+), an oxidized form of myoglobin (Fe2+), was confined in nanospaces of about 4 nm in diameter in mesoporous silica (FSM; folded-sheet mesoporous material), forming a metmyoglobin (Fe3+)-FSM nanoconjugate. The spectral characteristics of metmyoglobin (Fe3+)- and myoglobin (Fe2+)-FSM show an absorption curve quite similar to that of native metmyoglobin, indicating that myoglobin retains its higher-order structure in the pores of FSM. The metmyoglobin (Fe3+)-FSM conjugate had not only a peroxidase-like activity in the presence of hydrogen peroxide (a hydrogen acceptor) and 2,2-azino-bis(3-ethylbenzothiazoline)-6-sulfomic acid (ABTS) or guaiacol (a hydrogen donor) but also an advanced molecular recognition ability enabling it to distinguish between ABTS and guaiacol. Furthermore, the metmyoglobin (Fe3+)-FSM showed the peroxidase-like activity even in an organic media using benzoyl peroxide as the hydrogen acceptor and leucocrystal violet as the hydrogen donor. The simple immobilization of metmyoglobin (Fe3+) into FSM results in enhanced catalytic activity in organic media compared to that of native metmyoglobin (Fe3+).
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), Nigatake 4-2-1, Miyagino-ku, Sendai, 983-8551, Japan. t-itoh@ni-aist.go.jp
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Itoh
authors.forename: Ryo
authors.initials: R
authors.lastname: Ishii
authors.forename: Takeo
authors.initials: T
authors.lastname: Ebina
authors.forename: Takaaki
authors.initials: T
authors.lastname: Hanaoka
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Fukushima
authors.forename: Fujio
authors.initials: F
authors.lastname: Mizukami
mesh_terms: D000327:Adsorption; D002248:Carbon Monoxide / Q000737:chemistry; D008786:Metmyoglobin / Q000737:chemistry*; D010544:Peroxidases / Q000737:chemistry; D016062:Porosity; D017640:Silicates / Q000737:chemistry*
chemical_list: D017640:Silicates; D008786:Metmyoglobin; D002248:Carbon Monoxide; D010544:Peroxidases