Linked Life Data

15839684

Source:http://linkedlifedata.com/resource/pubmed/id/15839684

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
2005-4-20
pubmed:abstractText
The substrate specificity of 4-oxalocrotonate tautomerase (4-OT) is characterized by electrostatic interactions between positively charged arginine (Arg) side chains on the enzyme and the dianionic substrate, 4-oxalocrotonate. To generate specific hydrogen-bonding interactions with a monoanionic substrate analogue, we have introduced a urea functional group into the active site by replacing arginine side chains with isosteric citrulline (Cit) residues. This design was based on the complementarity between the urea functionality of citrulline and the uncharged amide function of the substrate, as opposed to the guanidinium-carboxylate electrostatic interaction between the wild-type enzyme and the natural substrate. Indeed, the synthetic (Arg39Cit)4-OT analogue catalyzed the tautomerization of the non-natural monoamide-monoacid substrate while it was a poor catalyst for the natural diacid substrate. The specificity of (Arg39Cit)4-OT for the monoamide-monoacid substrate relative to that of the diacid substrate was found to be 740-fold greater than that of the wild-type enzyme for tautomerization of the non-natural substrate as compared with the natural one. The role of electrostatic interactions in the tautomerization of the monoamide-monoacid substrate was probed in detail with several other Arg to Cit analogues of this enzyme. This study has demonstrated that chemical manipulation of the functional groups within the active site of an enzyme can modify its catalytic activity and substrate specificity in a predictable way, suggesting that the incorporation of noncoded amino acids into proteins has great promise for the development of new enzymatic mechanisms and new binding interactions.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0002-7863
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
127
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5862-8
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
A designed synthetic analogue of 4-OT is specific for a non-natural substrate.
pubmed:affiliation
Department of Chemistry and Institute of Catalysis Science and Technology, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't