Non-covalent intercalative binding of 7,8-dihydroxy-9,10-epoxybenzo(a)pyrene to DNA |
| |
Authors: | N E Geacintov H Yoshida V Ibanez R G Harvey |
| |
Institution: | 1. Chemistry Department, New York University, New York, N.Y. 10003 USA;2. Radiation and Solid State Laboratory, New York University, New York, N.Y. 10003 USA |
| |
Abstract: | When the benzo(a)pyrene diol epoxide (±)-7β,8α-dihydroxy-9α,10α-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene (BPDE) is mixed into a DNA solution, a 10nm red shift in the absorption maximum of BPDE appears at 354nm which is due to a non-covalent intercalation complex. The major reaction pathway at this intercalation site is the hydrolysis of BPDE to its tetraol which is accompanied by a decrease in the absorbance and a shift from 354 to 353nm (the latter is due to intercalated tetraol). The non-covalent binding constants are approximately 8200M?1 for BPDE and 3300M?1 for the tetraol at 25°C, pH 7.0. Covalent adduct formation between BPDE and DNA occurs either at another, external binding site, or after some rearrangement of the intercalated BPDE, since covalent adducts display a 345nm absorption maximum (2nm red shift only). |
| |
Keywords: | |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|