Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
PEROXIDASES FROM TULIP BULBS (TULIPA-FOSTERIANA, L.) OXIDIZE XENOBIOTICS N-NITROSODIMETHYLAMINE AND N-NITROSO-N-METHYLANILINE IN-VITRO
Autore:
STIBOROVA M; HANSIKOVA H;
Indirizzi:
CHARLES UNIV,DEPT BIOCHEM PRAGUE 12840 2 CZECH REPUBLIC
Titolo Testata:
Collection of Czechoslovak Chemical Communications
fascicolo: 11, volume: 62, anno: 1997,
pagine: 1804 - 1814
SICI:
0010-0765(1997)62:11<1804:PFTB(L>2.0.ZU;2-0
Fonte:
ISI
Lingua:
ENG
Soggetto:
1-PHENYLAZO-2-HYDROXYNAPHTHALENE SUDAN-I; AVOCADO PERSEA-AMERICANA; NON-AMINOAZO DYE; HIGHER-PLANTS; ACTIVATION; DNA; CYTOCHROME-P-450; ENZYMES; BINDING; YEAST;
Keywords:
PLANTS; EXOGENOUS CHEMICALS; N-DEMETHYLATION; N-NITROSAMINES; ENZYME KINETICS; ENZYMATIC OXIDATION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
36
Recensione:
Indirizzi per estratti:
Citazione:
M. Stiborova e H. Hansikova, "PEROXIDASES FROM TULIP BULBS (TULIPA-FOSTERIANA, L.) OXIDIZE XENOBIOTICS N-NITROSODIMETHYLAMINE AND N-NITROSO-N-METHYLANILINE IN-VITRO", Collection of Czechoslovak Chemical Communications, 62(11), 1997, pp. 1804-1814

Abstract

Tulip bulbs (Tulipa fosteriana, L.) contain peroxidases catalyzing the oxidation of the xenobiotics N-nitrosodimethylamine (NDMA) and N-nitroso-N-methylaniline (NMA). Three anionic (A(1), A(2), A(3)) and four cationic (B, C, D, E) peroxidases were purified from this tissue, partially characterized and used for kinetic studies. Demethylation of NDMA and NMA producing formaldehyde is catalyzed by one anionic (A(1)) and three cationic (C, D, E) peroxidases. The oxidation of NDMA by tulipperoxidases exhibits the Michaelis-Menten kinetics. The apparent Michaelis constant and the maximal velocity values for this substrate weredetermined. On the other hand, non-Michaelian kinetics for the NMA oxidation were observed with tulip peroxidases. The most abundant cationic peroxidase (peroxidase C) was used for detailed enzymatic studies. In addition to formation of formaldehyde, methylaniline, aniline, 4-aminophenol and phenol were found to be metabolites formed from NMA. Phenol was formed presumably by N-demethylation via a benzenediazonium ion, while methylaniline, aniline and 4-aminophenol were products of denitrosation of the substrate. The efficiencies of plant peroxidases to oxidize NDMA and NMA in vitro are compared with those of cytochromes P450 and discussed.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 25/11/20 alle ore 07:11:56