Interaction of mutagenic tryptophan pyrolysate with DNA. CD spectral study on the binding specificity.
The interactions of DNA duplexes with 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), a potent mutacarcinogen isolated from tryptophan pyrolysate, have been studied using CD spectroscopy. The results are that (a) the spectral change of B-form DNA caused by the interaction with Trp-P-1 is biphasic, i.e. the enlargement of CD bands characteristic to the B-DNA conformation in the range of r ([Trp-P-1]/ DNA]) = 0-2.5, followed by the rapid transition to the non-B conformation at r > 2.5; (b) this transition degree of B to non-B conformation of DNA is not necessarily dependent on the G-C content; and (c) the salt-induced Z-DNA is transformed to B-DNA (0 < r < 0.1) and then to non-B-DNA (r > 5), depending on the concentration of Trp-P-1 added. These data indicate that the non-covalent interaction of Trp-P-1 with DNA is mainly dependent on the B-DNA conformation.
Inohara
T
T
Department of Physical Chemistry, Osaka University of Pharmaceutical Sciences, Japan.
Tarui
M
M
Doi
M
M
Inoue
M
M
Ishida
T
T
D001483:Base Sequence; D002243:Carbolines / Q000737:chemistry*; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D009153:Mutagens / Q000737:chemistry*; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D014364:Tryptophan / Q000737:chemistry*
D002243:Carbolines; D009153:Mutagens; D009838:Oligodeoxyribonucleotides; C019133:3-amino-1-methyl-5H-pyrido(4,3-b)indole; D014364:Tryptophan; D004247:DNA