Linked Life Data

9188729

Source:http://linkedlifedata.com/resource/pubmed/id/9188729

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
23
pubmed:dateCreated
1997-7-14
pubmed:abstractText
We have examined the equilibrium binding of a series of synthetic oligoarginines (net charge z = +2 to +6) containing tryptophan to poly(U), poly(A), poly(C), poly(I), and double-stranded (ds) DNA. Equilibrium association constants, K(obs), measured by monitoring tryptophan fluorescence quenching, were examined as functions of monovalent salt (MX) concentration and type, as well as temperature, from which deltaG(standard)obs, deltaH(obs), and deltaS(standard)obs were determined. For each peptide, K(obs) decreases with increasing [K+], and the magnitude of the dependence of K(obs) on [K+], delta log K(obs)/delta log[K+], increases with increasing net peptide charge. In fact, the values of delta log K(obs)/delta log[K+] are equivalent for oligolysines and oligoarginines possessing the same net positive charge. However, the values of K(obs) are systematically greater for oligoarginines binding to all polynucleotides, when compared to oligolysines with the same net charge. The origin of this difference is entirely enthalpic, with deltaH(obs), determined from van't Hoff analysis, being more exothermic for oligoarginine binding. The values of deltaH(obs) are also independent of [K+]; therefore, the salt concentration dependence of deltaG(standard)obs is entirely entropic in origin, reflecting the release of cations from the nucleic acid upon complex formation. These results suggest that hydrogen bonding of arginine to the phosphate backbone of the nucleic acids contributes to the increased stability of these complexes.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
36
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7272-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Thermodynamics of oligoarginines binding to RNA and DNA.
pubmed:affiliation
Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.