Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1975-5-10
pubmed:abstractText
The effects of ethanol, ethylene glycol, dioxane, and other organic co-solvents upon the hydrogen exchange rates of randomly coiled oxidized RNase, native RNase, and native trypsin have been measured. The exchange rate of oxidized RNase, the model compound for the proton transfer step in hydrogen exchange, is decreased by all of the co-solvents studied at temperatures in the range 3-20 degrees. This has been ascribed to the combined effects of the disruption of peptide bond solvation due to a reduction in the concentration of water, and of changes in [OH-] ion concentration due to changes in the acid dissociation constant of water, Kw. The solvent dependence for both native RNase and native trypsin is similar in all of the solvents studied. At a low temperature (3-20 degrees), the exchange rates go through a minimum as the solvent concentration is increased. At higher temperatures (20-35 degrees) the exchange rates are increased at all concentrations of the co-solvent. The apparent rate minimum at lower temperatures is due to two opposing effects. Co-solvents decrease the rate of exchange that occurs directly from the folded molecule. At higher concentrations and higer temperature. The decrease in rates for exchange directly from folded protein is primarily due to the effects on the proton transfer step, and not to binding or the solvent effects on protein structure. The solvents used in this study have no apparent effect on conformational processes contributing to the hydrogen exchange process in folded proteins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
250
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
440-4
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1975
pubmed:articleTitle
The solvent dependence of hydrogen exchange kinetics of folded proteins.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.