Linked Life Data

1898739

Source:http://linkedlifedata.com/resource/pubmed/id/1898739

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1991-2-12
pubmed:abstractText
We have found that many dianionic species, at millimolar concentrations, significantly activate or inhibit the bovine carbonic anhydrase III-catalyzed hydration of CO2. Dianionic species such as HPO2-4 and SO2-3, with pKb values near 7, are activators, whereas weakly basis species such as SO2-4 act as inhibitors. Both activation and inhibition are partial hyperbolic in nature and do not appear to compete with monoanionic linear inhibitors like N-3. Our kinetic data are consistent with a formal mechanism of action for carbonic anhydrase III that is directly analogous to that of carbonic anhydrase II, in which Lys-64 of carbonic anhydrase III can act as an intramolecular H+ transfer group during CO2 hydration. Our data suggest that dianionic inhibitors depress the rate of H+ transfer during turnover by stabilizing the protonated form of Lys-64. We postulate that dianionic activators enhance the rate of a rate-limiting H+ transfer step in the mechanism, probably by acting directly as H+ acceptors.
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
15
pubmed:volume
266
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
933-41
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Activation and inhibition of bovine carbonic anhydrase III by dianions.
pubmed:affiliation
Department of Chemistry, Colgate University, Hamilton, New York 13346.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't