Linked Life Data

7849034

Source:http://linkedlifedata.com/resource/pubmed/id/7849034

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1995-3-13
pubmed:abstractText
The effects of temperature, pH, and magnesium ion concentration on the internal equilibrium of the hammerhead ribozyme reaction were determined in order to better understand why the ribozyme-bound substrate RNA is 99% cleaved at equilibrium. Cleavage of substrate is more efficient at higher temperatures because a large entropy gain upon cleavage outweighs an enthalpically unfavorable generation of a 2',3'-cyclic phosphate product. The delta H of the reaction is as expected from bond energies, and provides no indication of high-energy ribozyme/substrate interactions that are lost upon cleavage. The rate constants of both cleavage and ligation increase log-linearly with pH between 5.6 and 8.0, indicating that a deprotonation step is required for both cleavage and ligation. The magnesium ion dependence of the internal equilibrium suggests that either the number or the affinity of bound magnesium ions changes upon cleavage. Since the very slow rate of hydrolysis of the 2',3'-cyclic terminus of product P1 was unaffected by the presence of the ribozyme, we conclude that hydrolysis is not a significant side reaction of the hammerhead cleavage reaction.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1744-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
The internal equilibrium of the hammerhead ribozyme reaction.
pubmed:affiliation
Department of Chemistry and Biochemistry, University of Colorado, Boulder 80309-0215.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.