Linked Life Data

9054542

Source:http://linkedlifedata.com/resource/pubmed/id/9054542

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1997-3-26
pubmed:abstractText
A high-resolution proton NMR study has been performed on a hybrid duplex formed by a methylphosphonate (MP) oligodeoxyribonucleotide (MPO) and its target oligoribonucleotide, d(T(MP)CC(MP)-TT(MP)AG(MP)CT(MP)CC(MP)TG) x r(CAGGAGCUAAGGA), where MP corresponds to positions of methylphosphonate linkages in the pure R(p) stereoconfiguration. MP-containing analogs of DNA are reported to be effective antisense agents capable of specifically inhibiting protein synthesis with the R(p) chiral MPOs exhibiting greater affinity for the target mRNA than their S(p) counterparts. Nearly complete proton resonance assignments of the hybrid duplex have been made using two-dimensional nuclear Overhauser effect (2D NOE) spectra, at three different mixing times, and double quantum-filtered COSY (2QF-COSY) spectra. The 2QF-COSY cross-peak patterns which are resolved have been analyzed qualitatively to suggest sugar conformations. Distance restraints have been obtained from the 2D NOE spectra of the duplex in D(2)O. These interproton distance restraints were determined using a complete relaxation matrix method to improve accuracy. Specifically, a new approach termed RANDMARDI has been utilized to calculate these distance restraints, accounting for spectral noise and errors in 2D NOE peak volume integration. The calculated interproton distances and sugar puckers have been analyzed to assess the solution conformation of the hybrid. The hybrid duplex appears to have an overall solution structure which is distinct from standard B- and A-forms, but the RNA strand exhibits features of the A-form. The absence of H1'-H2' cross-peaks in the 2QF-COSY spectrum indicates a C3'-endo type of conformation for ribose sugars in the RNA strand. The deoxyriboses in the antisense DNA strand exhibit a mixed behavior with almost equal scalar coupling constant values for H1'-H2' and H1'-H2" and a strong H3'-H4' 2QF-COSY peak pattern. Variations in calculated values of interproton distances and sixth-root R factor analysis of experimental intensities indicate that the hybrid duplex may have a DNA strand with significant conformational plasticity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
4
pubmed:volume
36
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2371-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
High-resolution NMR of an antisense DNA x RNA hybrid containing alternating chirally pure Rp methylphosphonates in the DNA backbone.
pubmed:affiliation
Department of Pharmaceutical Chemistry, University of California, San Francisco 94143-0446, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.