Linked Life Data

18004855

Source:http://linkedlifedata.com/resource/pubmed/id/18004855

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
49
pubmed:dateCreated
2007-12-6
pubmed:abstractText
Tetraphenyl porphyrin substituted deoxyuridine was used as a building block to create discrete multiporphyrin arrays via site specific incorporation into DNA. The successful covalent attachment of up to 11 tetraphenyl porphyrins in a row onto DNA shows that there is virtually no limitation in the amount of substituents, and the porphyrin arrays thus obtained reach the nanometer scale (approximately 10 nm). The porphyrin substituents are located in the major groove of the dsDNA and destabilize the duplex by deltaT(m) 5-7 degrees C per porphyrin modification. Force-field structure minimization shows that the porphyrins are either in-line with the groove in isolated modifications or aligned parallel to the nucleobases in adjacent modifications. The CD signals of the porphyrins are dominated by a negative peak arising from the intrinsic properties of the building block. In the single strands, the porphyrins induce stabilization of a secondary helical structure which is confined to the porphyrin modified part. This arrangement can be reproduced by force-field minimization and reveals an elongated helical arrangement compared to the double helix of the porphyrin-DNA. This secondary structure is disrupted above approximately 55 degrees C (T(p)) which is shown by various melting experiments. Both absorption and emission spectroscopy disclose electronic interactions between the porphyrin units upon stacking along the outer rim of the DNA leading to a broadening of the absorbance and a quenching of the emission. The single-stranded and double-stranded form show different spectroscopic properties due to the different arrangement of the porphyrins. Above T(p) the electronic properties (absorption and emission) of the porphyrins change compared to room temperature measurements due to the disruption of the porphyrin stacking at high temperature. The covalent attachment of porphyrins to DNA is therefore a suitable way of creating helical stacks of porphyrins on the nanometer scale.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1520-5126
pubmed:author
pubmed:issnType
Electronic
pubmed:day
12
pubmed:volume
129
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
15319-29
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
DNA as supramolecular scaffold for porphyrin arrays on the nanometer scale.
pubmed:affiliation
Contribution from the School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't