Photocleavage of plasmid DNA by the prophyrin meso-tetrakis[4-(carboxymethyleneoxy)phenyl]porphyrin
DSpace at IIT Bombay
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Title |
Photocleavage of plasmid DNA by the prophyrin meso-tetrakis[4-(carboxymethyleneoxy)phenyl]porphyrin
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Creator |
CHATTERJEE, SR
SHETTY, SJ DEVASAGAYAM, TPA SRIVASTAVA, TS |
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Subject |
single-stranded-dna
circular-dichroism porphyrin oxygen binding intercalation constants complexes cleavage charges porphyrin pbr322 dna photocleavage single stand breaks singlet oxygen soret band circular dichroism fluorescence energy transfer |
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Description |
meso-Tetrakis [4-(carboxymethylenzoxy)phenyl]porphyrin (H(2)T4CPP) cleaves pBR322 plasmid DNA to single strand breaks in the presence of molecular oxygen and visible light. The above photocleavage was much more efficient in D2O buffer of sodium phosphate (pD = 7.4) than H2O buffer of sodium phosphate (pH = 7.4). In addition this photocleavage of plasmid DNA was inhibited in the presence of sodium azide, lipoic acid, tert-butanol or mannitol suggesting the involvement of O-1(2) and OH in the photocleavage of plasmid DNA. The photocleavage was observed to be more efficient in the presence of H2CPP than in the presence of H(2)T4CPP [meso-tetrakis(4-carboxy-phenyl) porphyrin]. Our spectral studies using UV-visible, fluorescence and circular dichroism techniques suggest that H(2)T4CPP binds to DNA while H(2)T4CPP does not, Thus, the difference in photocleavage may be caused by the nonbinding of H2CPP and by the binding of H(2)T4CPP to calf thymus (CT) DNA. (C) 1997 Elsevier Science S.A.
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Publisher |
ELSEVIER SCIENCE SA
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Date |
2011-07-28T16:16:43Z
2011-12-26T13:02:52Z 2011-12-27T05:50:08Z 2011-07-28T16:16:43Z 2011-12-26T13:02:52Z 2011-12-27T05:50:08Z 1997 |
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Type |
Article
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Identifier |
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY, 41(1-2), 128-135
1011-1344 http://dx.doi.org/10.1016/S1011-1344(97)00094-8 http://dspace.library.iitb.ac.in/xmlui/handle/10054/7445 http://hdl.handle.net/10054/7445 |
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Language |
en
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