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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2006-12-28
pubmed:abstractText
The cleavage of P1-(7-methylguanosyl-5') P3-(guanosyl-5') triphosphate, a RNA 5'-cap model, by 2-hydroxyethyl- (6a-6c) and 2-aminoethyl- (7a-7c) substituted macrocycles in the presence and absence of Zn2+ and Cu2+ ions has been studied at pH 7.2 and 60 degrees. In the presence of the metal ions, hydrolysis of the phosphate group is enhanced. The mono- and dinuclear Zn2+ complexes promote solely the phosphate hydrolysis, whereas the corresponding Cu2+ complexes accelerate both the phosphate hydrolysis and the imidazole ring opening of the 7-methylguanine base. In the absence of the metal ions, the macrocycles mainly promote breakdown of the 7-methylguanine base, most probably by enhancing the nucleophilic attack of hydroxide ion on the C(8)-atom by shielding the repulsive negative charge on the phosphate moiety. The 2-hydroxyethyl and 2-aminoethyl side arms exhibit a two- to three-fold rate acceleration. Opening of the imidazole ring eventually results in cleavage of the triphosphate bridge.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1612-1880
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
2
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
92-103
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Metal ion complexes of macrocyclic polyamines enhance both the phosphate hydrolysis and imidazole ring opening of RNA 5'-cap structure.
pubmed:affiliation
University of Turku, Department of Chemistry, FIN-20014 Turku.
pubmed:publicationType
Journal Article