title: Mechanism of inhibition of wt-dihydrofolate reductase from E. coli by tea epigallocatechin-gallate.
abstract: Dihydrofolate reductase (DHFR) is a ubiquitous enzyme involved in major biological process, including DNA synthesis and cancer inhibition, and its modulation is the object of extensive structural, kinetic, and pharmacological studies. In particular, earlier studies showed that green tea catechins are powerful inhibitors of bovine liver and chicken liver DHFR. In this article, we report the results of inhibition kinetics for the enzyme from another source (DHFR from E. coli) exerted by (-)-epigallocatechingallate (EGCG). Using different analytical techniques, we reported that EGCG acts as a bisubstrate inhibitor on the bacterial DHFR. Moreover, the combined approach of biosensor, kinetic, and molecular modelling analysis disclosed the ability of EGCG to bind to the enzyme both on substrate (DHF) and cofactor (NADPH) site. Collectively, our data have confirmed the selectivity of antifolate compounds with respect to the different source of enzyme (bacterial or mammalian DHFR) and the possible role of tea catechins as chemopreventive agents.
authors.affiliation: Department of Molecular, Cellular and Animal Biology, University of Camerino, Via Gentile III da Varano, 62032, Camerino (MC), Italy. michele.spina@unicam.it
authors.forename: Michele
authors.initials: M
authors.lastname: Spina
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Cuccioloni
authors.forename: Matteo
authors.initials: M
authors.lastname: Mozzicafreddo
authors.forename: Francesca
authors.initials: F
authors.lastname: Montecchia
authors.forename: Stefania
authors.initials: S
authors.lastname: Pucciarelli
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Eleuteri
authors.forename: Evandro
authors.initials: E
authors.lastname: Fioretti
authors.forename: Mauro
authors.initials: M
authors.lastname: Angeletti
mesh_terms: D000818:Animals; D015374:Biosensing Techniques; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002417:Cattle; D004800:Enzymes, Immobilized / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology*; D005493:Folic Acid Antagonists / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D008958:Models, Molecular; D013662:Tea / Q000737:chemistry*; D013762:Tetrahydrofolate Dehydrogenase / Q000378:metabolism*; D013816:Thermodynamics
chemical_list: D004800:Enzymes, Immobilized; D005493:Folic Acid Antagonists; D013662:Tea; D002392:Catechin; C045651:epigallocatechin gallate; D013762:Tetrahydrofolate Dehydrogenase