6533b852fe1ef96bd12aae59

RESEARCH PRODUCT

Trichinella spiralisThymidylate Synthase: Developmental Pattern, Isolation, Molecular Properties, and Inhibition by Substrate and Cofactor Analogues

Wojciech RodeRafal MichalskiMariusz WraniczZbigniew ZielińskiMagdalena DabrowskaKrzysztof Pawelczak

subject

Thymidine kinase activityBiophysicsThiophenesBiologyBiochemistryThymidylate synthaseChromatography AffinityGene Expression Regulation EnzymologicCofactorStructure-Activity RelationshipFolic AcidNon-competitive inhibitionFluorodeoxyuridylateAnimalsHumansEnzyme InhibitorsMolecular BiologyTrichinella spiralischemistry.chemical_classificationATP synthaseMusclesGene Expression Regulation DevelopmentalSubstrate (chemistry)Thymidylate SynthaseCell BiologyMolecular biologyLiver RegenerationRatsKineticsEnzymeLiverchemistryBiochemistryLarvaQuinazolinesbiology.proteinSpecific activity

description

Abstract Thymidylate synthase specific activity was found to remain at a constant level in crude extracts from muscle larvae, isolated (1-15 months after infection) by pepsin-HCl digestion, as well as from adult worms ofTrichinella spiralis.The enzyme was purified and its molecular (monomer mol. wt 35 kD) and kinetic (sequential mechanism with the Kmvalues 3.1 and 19 μM for dUMP and N5,10-methylenetetrahydrofolate, respectively) properties determined. 5-Fluoro-dUMP was a competitive, slow-binding inhibitor of the parasite enzyme. N5,10-methylenetetrahydrofolate analogues 10-propargyl-5,8-dideazafolate (CB3717), ZD1694, BW1843U89, and AG337 were weaker inhibitors of the parasite than regenerating rat liver enzyme. Inhibition by 10-propargyl-5,8-dideazafolate was strengthened by an increasing number of glutamate residues. Thymidine kinase activity could not be detected in the muscle larvae crude extracts.

https://doi.org/10.1006/bbrc.1996.1679