Inhibition of CpLIP2 Lipase Hydrolytic Activity by Four Flavonols (Galangin, Kaempferol, Quercetin, Myricetin) Compared to Orlistat and Their Binding Mechanisms Studied by Quenching of Fluorescence

Ruba Nasri (1) , Luc Bidel (2) , Nathalie Rugani (3) , Véronique Perrier (1) , Frédéric Carriere (4) , Eric Dubreucq (1) , Christian Jay-Allemand (1)

1 UMR IATE - Ingénierie des Agro-polymères et Technologies Émergentes
2 UMR AGAP - Amélioration génétique et adaptation des plantes méditerranéennes et tropicales
3 UM - Université de Montpellier
4 BIP - Bioénergétique et Ingénierie des Protéines

The inhibition of recombinant CpLIP2 lipase/acyltransferase from Candida parapsiolosis was considered a key model for novel antifungal drug discovery and a potential therapeutic target for candidiasis. Lipases have identified recently as potent virulence factors in C. parapsilosis and some other yeasts. The inhibition effects of orlistat and four flavonols (galangin, kaempferol, quercetin and myricetin) characterized by an increasing degree of hydroxylation in B-ring, were investigated using ethyl oleate hydrolysis as the model reaction. Orlistat and kaempferol (14 µM) strongly inhibited CpLIP2 catalytic activity within 1 min of pre-incubation, by 90% and 80%, respectively. The relative potency of flavonols as inhibitors was: kaempferol > quercetin > myricetin > galangin. The results suggested that orlistat bound to the catalytic site while kaempferol interacted with W294 on the protein lid. A static mechanism of interactions between flavonols and CpLIP2 lipase was confirmed by fluorescence quenching analyses, indicating that the interactions were mainly driven by hydrophobic bonds and electrostatic forces. From the Lehrer equation, fractions of tryptophan accessibility to the quencher were evaluated, and a relationship with the calculated number of binding sites was suggested

Mots clés: Recombinant CpLIP2 lipase; Flavonols; Orlistat; Fluorescence quenching; Hydroxylation; Tryptophan residues; Docking; tryptophan; inhibition; molecular model

Mots clés: flavanol; acétyltransférase; tryptophane; hydroxylation; inhibition; lipase; macromolécule; quenching; modèle moléculaire

Domaines: Ingénierie des aliments

Ruba Nasri, Luc Bidel, Nathalie Rugani, Véronique Perrier, Frédéric Carriere, et al.. Inhibition of CpLIP2 Lipase Hydrolytic Activity by Four Flavonols (Galangin, Kaempferol, Quercetin, Myricetin) Compared to Orlistat and Their Binding Mechanisms Studied by Quenching of Fluorescence. Molecules, 2019, 24 (16), ⟨10.3390/molecules24162888⟩. ⟨hal-02273367⟩