Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1982-8-7
pubmed:abstractText
The study of the temperature dependence of the hydrolysis of cytidine 2',3'-phosphate by bovine pancreatic ribonuclease A (EC 3.1.27.5) at pH 7.0 by using the pH-stat method showed a transition at 4 degrees C [J. A. Biosca and C. M. Cuchillo (1980) Biochem. J. 189, 655-657]. The breaks found in the Van't Hoff and Arrhenius plots at pH 7.0 were confirmed in the present work by following the reaction spectrophotometrically with a stopped-flow spectrophotometer adapted to the use of sub-zero temperatures. Similar results were found at pH 5.5. In addition it was found that the discontinuity disappears when 40% ethyleneglycol is present in the reaction mixture. However, in this latter instance a discontinuity around 0 degrees C appears in the Arrhenius plot. To explore the possibility that all these effects were due to a conformational transition in the protein, thermal perturbation experiments were carried out with the enzyme. A change in the slope of the plot of delta A290 as a function of temperature was found around 6 degrees C at pH 7.0 but not at pH 5.5. The results reported here can be interpreted as due to a change in the protein structure induced by the change of the structure of water. The studies carried out in the presence of ethyleneglycol also open the way to the cryoenzymological experimentation on ribonuclease.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:volume
124
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
151-6
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1982
pubmed:articleTitle
Influence of the structure of water on the hydrolysis of cytidine 2',3'-phosphate catalysed by bovine pancreatic ribonuclease A.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't