Linked Life Data

3124879

Source:http://linkedlifedata.com/resource/pubmed/id/3124879

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1988-4-7
pubmed:abstractText
Steady-state and equilibrium kinetic properties of native bovine carbonic anhydrase III (carbonate hydrolyase, EC 4.2.1.1) and a derivative modified with methyl methanethiosulfonate were investigated. The modified enzyme has a markedly increased CO2 hydration activity compared to the native form with a 3-times higher value of kcat and a 6-10-times higher value of kcat/Km. Qualitatively, the activated enzyme shows the same kinetic behavior as native isoenzyme III. This is reflected in similar pH dependences of the kinetic parameters for CO2 hydration, similar solvent hydrogen isotope effects on these parameters, similar deviations from Michaelis-Menten kinetics for the HCO3- dehydration reaction, and similar behavior of the kinetics of CO2/HCO3- exchange at chemical equilibrium as measured by a 13C-NMR magnetization transfer technique. It is concluded that the conversion of -SH groups to -S-S-CH3 moieties does not change the catalytic mechanism, but leads to an increased rate of CO2/HCO3- interconversion as well as to an increased rate of proton transfer between the active site and the reaction medium.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
953
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
79-85
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
A comparison of the kinetic properties of native bovine muscle carbonic anhydrase and an activated derivative with modified thiol groups.
pubmed:affiliation
Department of Biochemistry, University of Umeå, Sweden.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't