title: DNA-binding and photocleavage properties of cationic porphyrin-anthraquinone hybrids with different lengths of links.
abstract: Four cationic porphyrin-anthraquinone (Por-AQ) hybrids differing in lengths of flexible alkyl linkage, 5-[4-(1-N-anthraquinonon-yl)-L-oxophenyl]-10,15,20-tris(N-methylpyridinium-4-yl)porphyrin triiodide, (L = acetyl, pentanoyl, octanoyl, undecanoyl, designed as [AQATMPyP]I3, [AQPTMPyP]I3, [AQOTMPyP]I3 and [AQUTMPyP]I3, respectively, see Fig. 1), were synthesized and their interactions with DNA were investigated. The results of spectroscopic, denaturation and viscosity measurements suggest that [AQATMPyP]I3 binds to DNA through non-intercalative mode while the other three hybrids with longer links bind via bis-intercalative mode. Ethidium bromide (EB) competition experiment was carried out to determine the binding constants (Kb) of these compounds for CT DNA, and [AQPTMPyP]I3 shows the largest Kb among these hybrids. The photocleavage mechanism and wavelength-dependent cleaving abilities of these hybrids to pBR322 plasmid DNA were also comparably investigated.
authors.affiliation: MOE Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, No. 135, Xingangxi Road, Guangzhou 510275, PR China.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhao
authors.forename: Lian-Cai
authors.initials: LC
authors.lastname: Xu
authors.forename: Jin-Wang
authors.initials: JW
authors.lastname: Huang
authors.forename: Bo
authors.initials: B
authors.lastname: Fu
authors.forename: Han-Cheng
authors.initials: HC
authors.lastname: Yu
authors.forename: Wei-Hong
authors.initials: WH
authors.lastname: Zhang
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
authors.forename: Jun-Hua
authors.initials: JH
authors.lastname: Yao
authors.forename: Liang-Nian
authors.initials: LN
authors.lastname: Ji
mesh_terms: D000880:Anthraquinones / Q000737:chemistry*; D002412:Cations; D002621:Chemistry / Q000379:methods; D004247:DNA / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D004996:Ethidium / Q000737:chemistry; D007364:Intercalating Agents / Q000494:pharmacology; D007700:Kinetics; D008956:Models, Chemical; D010777:Photochemistry / Q000379:methods*; D010957:Plasmids / Q000378:metabolism; D011166:Porphyrins / Q000737:chemistry*; D011485:Protein Binding; D013696:Temperature
chemical_list: D000880:Anthraquinones; D002412:Cations; D007364:Intercalating Agents; D011166:Porphyrins; D004247:DNA; D004996:Ethidium