title: Peroxidase-like catalytic activity of Mn- and Fe-tetrakis(4-carboxyphenyl)porphines bound to aminopropyl-glass bead in oxidative reaction of heterocyclic amines.
abstract: Fe- or Mn-tetrakis(4-carboxyphenyl)porphine (Fe- and Mn-TCPP) bound to aminopropyl-glass bead (Fe- and Mn-TCPP(g)s) was examined for the peroxidase (POD)-like function in order to develop a solid catalyst which can exhibit POD-like activity without adsorbing heterocyclic amines (HCAs). Mn-TCPP in aqueous solution had only a slight POD-like catalytic activity on HCAs (IQ and MeIQ). As for Fe-TCPP, it was impossible to examine the POD-like activity since it reacted with hydrogen peroxide in a liquid reaction system. However, both Fe- and Mn-TCPP when immobilized on aminopropyl-glass bead via peptide bond (Fe- and Mn-TCPP(g)s), catalyzed the oxidative reaction of mutagenic HCAs with hydrogen peroxide. The catalytic activity of Fe- and Mn-TCPP(g)s was investigated in more detail using as a substrate IQ and MeIQ which were oxidized more rapidly among the tested HCAs. Consequently, the optimal conditions for the oxidative reaction catalyzed by Fe- and Mn-TCPP(g)s were determined. In addition, ESI-mass and absorption spectra of oxidation products of IQ and MeIQ showed that they are dimers. Thus, it was demonstrated that a solid catalyst with POD-like activity can be obtained by immobilizing Fe- and Mn-TCPPs on aminopropyl-glass beads.
authors.affiliation: Department of Pharmaceutical Sciences, Graduate School of Medicine and Dentistry and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-Naka, Okayama, Japan.
authors.forename: Youji
authors.initials: Y
authors.lastname: Kitamura
authors.forename: Masaki
authors.initials: M
authors.lastname: Mifune
authors.forename: Daiki
authors.initials: D
authors.lastname: Hino
authors.forename: Saori
authors.initials: S
authors.lastname: Yokotani
authors.forename: Madoka
authors.initials: M
authors.lastname: Saito
authors.forename: Ikuko
authors.initials: I
authors.lastname: Tsukamoto
authors.forename: Akimasa
authors.initials: A
authors.lastname: Iwado
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Saito