Mechanism of inhibition of wt-dihydrofolate reductase from E. coli by tea epigallocatechin-gallate.
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.
Spina
Michele
M
Department of Molecular, Cellular and Animal Biology, University of Camerino, Via Gentile III da Varano, 62032, Camerino (MC), Italy. michele.spina@unicam.it
Cuccioloni
Massimiliano
M
Mozzicafreddo
Matteo
M
Montecchia
Francesca
F
Pucciarelli
Stefania
S
Eleuteri
Anna Maria
AM
Fioretti
Evandro
E
Angeletti
Mauro
M
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
D004800:Enzymes, Immobilized; D005493:Folic Acid Antagonists; D013662:Tea; D002392:Catechin; C045651:epigallocatechin gallate; D013762:Tetrahydrofolate Dehydrogenase