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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1990-8-15
pubmed:abstractText
We studied the effects of hexammine and tris(ethylene diamine) complexes of rhodium on the conformation of poly(dG-dC).poly(dG-dC) and poly(dG-m5dC).poly(dG-m5dC) using spectroscopic techniques and an enzyme immunoassay. Circular dichroism spectroscopic measurements showed that Rh(NH3)6(3+) provoked a B-DNA----Z-DNA----psi-DNA conformational transition in poly(dG-dC).poly(dG-dC). Using the enzyme immunoassay technique with a monoclonal anti-Z-DNA antibody, we found that the left-handedness of the polynucleotide was maintained in the psi-DNA form. In addition, we compared the efficacy of Rh(NH3)6(3+) and Rh(en)3(3+) to provoke the Z-DNA conformation in poly(dG-dC).poly(dG-dC) and poly(dG-m5dC.poly(dG-m5dC). The concentrations of Rh(NH3)6(3+) and Rh(en)3(3+) at the midpoint B-DNA----Z-DNA transition of poly(dG-dC).poly(dG-dC) were 48 +/- 2 and 238 +/- 2 microM, respectively. The psi-DNA form of poly(dG-dC).poly(dG-dC) was stabilized at 500 microM Rh(NH3)6(3+). With poly(dG-m5dC).poly(dg-m5dC), both counterions provoked the Z-DNA form at approximately 5 microM and stabilized the polynucleotide in this form up to 1000 microM concentration. These results show that trivalent complexes of Rh have a profound influence on the conformation of poly(dG-dC).poly(dG-dC) and its methylated derivative. Furthermore, the Rh complexes are capable of maintaining the Z-DNA form at concentration ranges far higher than that of other trivalent complexes. Our results also demonstrate that the efficacy of trivalent inorganic complexes to induce the B-DNA to Z-DNA transition of poly(dG-dC).poly(dG-dC) and poly(dG-m5dC).poly(dG-m5dC) is dependent on the nature of the ligand as well as the polynucleotide modification. Differences in charge density and hydration levels of counterions or base sequence- and counterion-dependent specific interactions between DNA and metal complexes might be possible mechanisms for the observed effects.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0739-1102
pubmed:author
pubmed:issnType
Print
pubmed:volume
7
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1221-35
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Conformational transitions of polynucleotides in the presence of rhodium complexes.
pubmed:affiliation
Department of Medicine, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick 08903.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't