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Photocleavage of plasmid pBR322 DNA by some anionic porphyrins

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Title Photocleavage of plasmid pBR322 DNA by some anionic porphyrins
 
Creator CHATTERJEE, SR
SRIVASTAVA, TS
KAMAT, JP
DEVASAGAYAM, TPA
 
Subject singlet oxygen
photodynamic therapy
strand breakage
light
metalloporphyrins
photosensitizers
oxidation
sites
plasmid dna
photocleavage
single-strand breaks
singlet oxygen
hydroxyl radical
energy transfer
electron transfer
anionic porphyrin
 
Description The;water-soluble porphyrins meso-tetrakis[4-(carboxymethyleneoxy)phenyl]porphyrin (H(2)T4CPP), meso-tetrakis[3-(carboxymethyleneoxy)phenyl]porphyrin (H(2)T3CPP) and meso-tetrakis[3,4-bis(carboxymethyleneoxy)phenyl]porphyrin (H(2)T3,4BCPP) cleave plasmid pBR322 DNA to single-strand breaks (SSBs) in the presence of molecular oxygen and visible light. These porphyrins induced SSBs in DNA as a function of irradiation time as well as porphyrin concentration. Under similar conditions (10 mu M or more), H2T3CPP showed more SSBs in DNA than the porphyrins H(2)T4CPP and H(2)T3,4BCPP. The DNA cleavage was more in D2O-based buffer than in H2O buffer. in addition, this DNA cleavage was inhibited by the presence of sodium azide and lipoic acid, which are potent quenchers of singlet oxygen (O-1(2)). These observations suggest the involvement of O-1(2) in photocleavage of DNA. Further, the DNA cleavage, to a limited extent, was also inhibited by tert-butanol and mannitol, both quenchers of hydroxyl radical ((OH)-O-.), suggesting the involvement of (OH)-O-. in photocleavage of DNA. Thus both O-1(2) and (OH)-O-. are involved in photocleavage of plasmid DNA by these porphyrins. (C) 1998 , Ltd.
 
Publisher JOHN WILEY & SONS LTD
 
Date 2011-08-17T00:14:12Z
2011-12-26T12:55:13Z
2011-12-27T05:43:56Z
2011-08-17T00:14:12Z
2011-12-26T12:55:13Z
2011-12-27T05:43:56Z
1998
 
Type Article
 
Identifier JOURNAL OF PORPHYRINS AND PHTHALOCYANINES, 2(4-5), 337-343
1088-4246
http://dx.doi.org/10.1002/(SICI)1099-1409(199807/10)2:4/5<337::AID-JPP80>3.0.CO;2-L
http://dspace.library.iitb.ac.in/xmlui/handle/10054/9675
http://hdl.handle.net/10054/9675
 
Language en