Linked Life Data

19591883

Source:http://linkedlifedata.com/resource/pubmed/id/19591883

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2009-8-24
pubmed:abstractText
The plant-like, bifunctional dihydrofolate reductase-thymidylate synthase (DHFR-TS) from malaria parasites has been a good target for drug development. Dihydrofolate reductase (DHFR) is inhibited by clinically established antimalarials, pyrimethamine and cycloguanil. Thymidylate synthase (TS) is the target of potent experimental antimalarials such as 5-fluoroorotate and 1843U89. Another enzyme in folate recycling, serine hydroxymethyltransferase (SHMT), produces 5,10-methylenetetrahydrofolate which, in many cells, is required for the de novo, biosynthesis of thymidine and methionine. Thus, the biochemical characterization of malarial SHMT was of interest. The principle, active Plasmodium falciparum SHMT (PfSHMT) was expressed in E. coli and purified using an N-terminal histidine tag. Unlike the plant enzyme, but like the host enzyme, PfSHMT requires the cofactor pyridoxal 5'-phosphate for enzymatic activity. The substrate specificities for serine, tetrahydrofolate, and pyridoxal 5'-phosphate were comparable to those for SHMT from other organisms. Antifolates developed for DHFR and TS inhibited SHMT in the mid-micromolar range, offering insights into the binding preferences of SHMT but clearly leaving room for improved new inhibitors. As previously seen with P. falciparum DHFR-TS, PfSHMT bound its cognate mRNA but not control RNA for actin. RNA binding was not reversed with enzyme substrates. Unlike DHFR-TS, the SHMT RNA-protein interaction was not tight enough to inhibit translation. Another gene PF14_0534, previously proposed to code for an alternate mitochondrial SHMT, was also expressed in E. coli but found to be inactive. This protein, nor DHFR-TS, enhanced the catalytic activity of PfSHMT. The present results set the stage for developing specific, potent inhibitors of SHMT from P. falciparum.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1872-9428
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
168
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
74-83
pubmed:dateRevised
2010-12-3
pubmed:meshHeading
pubmed-meshheading:19591883-Animals, pubmed-meshheading:19591883-Chromatography, Affinity, pubmed-meshheading:19591883-Cloning, Molecular, pubmed-meshheading:19591883-Coenzymes, pubmed-meshheading:19591883-Enzyme Inhibitors, pubmed-meshheading:19591883-Escherichia coli, pubmed-meshheading:19591883-Folic Acid Antagonists, pubmed-meshheading:19591883-Gene Expression, pubmed-meshheading:19591883-Glycine Hydroxymethyltransferase, pubmed-meshheading:19591883-Plasmodium falciparum, pubmed-meshheading:19591883-Protein Binding, pubmed-meshheading:19591883-Pyridoxal Phosphate, pubmed-meshheading:19591883-RNA, Messenger, pubmed-meshheading:19591883-Recombinant Fusion Proteins, pubmed-meshheading:19591883-Serine, pubmed-meshheading:19591883-Substrate Specificity, pubmed-meshheading:19591883-Tetrahydrofolates
pubmed:year
2009
pubmed:articleTitle
Catalytic and ligand-binding characteristics of Plasmodium falciparum serine hydroxymethyltransferase.
pubmed:affiliation
Department of Chemistry, University of Washington, Seattle, WA 98195, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural