Linked Life Data

8347590

Source:http://linkedlifedata.com/resource/pubmed/id/8347590

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
31
pubmed:dateCreated
1993-9-16
pubmed:abstractText
Site-directed mutants of human carbonic anhydrase III were used to examine the role of Thr-199 and its interaction with Phe-198 in the catalyzed hydration of CO2. Threonine-199 is a hydrogen bond acceptor for the zinc-bound water, and Phe-198 forms part of the hydrophobic side of the active-site cavity of carbonic anhydrase III. Catalytic activity for a total of five single and double mutants at residues 198 and 199 was determined by stopped-flow spectrophotometry and 18O exchange between CO2 and water measured by mass spectrometry. The replacement Thr-199-->Ala resulted in a 4-fold decrease in the kcat/Km for hydration of CO2. We tested the hypothesis that the 25-fold increase in the kcat/Km for hydration of CO2 accompanying the replacement Phe-198-->Leu in isozyme III is caused by changes in the interaction of Thr-199 with the zinc-bound water or the transition state for catalysis. Comparison of hydration of CO2 by the single and double mutants of isozyme III containing the replacements Thr-199-->Ala and Phe-198-->Leu was consistent with an interaction between these two sites.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7861-5
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Interaction and influence of phenylalanine-198 and threonine-199 on catalysis by human carbonic anhydrase III.
pubmed:affiliation
Department of Pharmacology and Therapeutics, University of Florida, Gainesville 32610.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.