VIRTUAL SCREENING and RAPID SCREENING ASSAYS in the discovery of NEW ANTIPARASITIC AGENTS

Transcription

1 VITUAL SCEEIG and APID SCEEIG ASSAYS in the discovery of EW ATIPAASITIC AGETS Stefania Ferrari DUG DISCVEY PCESS target identification and validation high-throughput technologies hit compounds identification focused technologies EW DUG lead compounds identification and optimization 1

2 FLATE-DEPEDET EZYMES AS DUGS TAGETS DA precursor biosynthesis Cancer Infections C 2H C 2H H H 2 H C 2H 10 -Formyl-THF H 2 THF C 2H AICA faica dgtp, datp AICA Tfase fga H 2 C 2H C 2H THF DA dttp GA Tfase C 2H H 2 H H C 2H 10 -Formyl-THF GA dump TS dtmp C 2H C 2H C 2H C 2H H Methylen-THF H 2 DHF Fosforibosylamine Glycine SHMT DHF C 2H ADPH/H + Serine H 2 THF C 2H ADP + 2

3 FLATE-DEPEDET EZYMES AS DUGS TAGETS DA precursor biosynthesis Cancer Infections species-specific enzymes structural differences in ubiquitous enzymes Thymidylate Synthase (TS) dump TS dtmp H H 2 H 2 H mthf DHF anticancer antibacterial, antiparasitic Specificity Index (SI) 3

4 PTeridine eductase 1 (PT1) leishmania, trypanosoma H H 2 H 2 H H 2 H ADPH H+ ADP+ ADPH H+ ADP+ antifolate drug resistance phenomena IDETIFICATI F EW FLATE-AALGS HIT/LEAD CMPUDS In house folate-analogs database apid screening bio-assays Bio-library hts hdhf EfTS LcTS LmTS-DHF LmPT1 TcTS-DHF TcPT1 hts hdhf EfTS LcTS LmTS-DHF LmPT1 TcTS-DHF TcPT1 inhibition activity profiles 4

5 Folate-analogs database database size reduction 5 > 400 compounds 8 in vitro anticancer activity (CI) water solubility newly synthesized molecules 131 compounds tested Bio-library human Thymidylate Synthase (hts) human Dihydrofolate eductase (hdhf) Enterococcus faecalis TS (EfTS) Escherichia coli TS () Lactobacillus casei TS (LcTS) Leishmania major TS-DHF (LmTS-DHF) Pteridine eductase 1 (LmPT1) Trypanosoma cruzi TS-DHF (TcTS_DHF) Pteridine eductase 1 (TcPT1) 5

6 a p q c g i l f r a b c d e f g h i hts hdhf EfTS LcTS LmTS-DHF LmPT1 TcTS-DHF TcPT1 hts hdhf EfTS LcTS LmTS-DHF LmPT1 TcTS-DHF TcPT1 Specificity profiles (SI = Ki xe / Ki he ) anticancer activity Activity (Ki) antibacterial antiparasitic activity 8 new hit compounds From the inhibition activity profiles SA Bio-clustering analyses structural features: activity specificity analogs database search already synthesized better compounds 6

7 H HC H CH H2 4 CH H2 3 1 HC CH H2 H CH H2 H HC HC CH H2 CH H2 CH H2 CH H2 HC CH H2 H HC HC CH H2 CH H2 CH H2 Perspective on parasite in vitro activity selected hits enzymatic kinetic studies accurate inhibition activity profiles -ray crystallography new derivatives enzyme interaction model synthesis molecular modeling structure-based modification design IDETIFICATI F EW -FLATE-AALGS HIT/LEAD CMPUDS vs TcPT LUDI (InsightII) Virtual Sceening ACD: ~ Small molecules database TcPT1: Target 3D model ew chemical entities 7

8 TcPT1 P218 F ADP+ Y S103 D169 L176 K186 Y182 folate-dependent enzymes bio-library on parasite in vitro activity selected compounds new derivatives enzymatic assays inhibition activity profiles selection: activity, specificity scaffold-like properties synthesis new scaffold(s) structure-based library design Perspective molecular modeling refined enzyme interaction model 8

9 Acknowledgements Prof. Maria Paola Costi Donatella Tondi Stefania Ferrari Alberto Venturelli Samuele Calò Antonio Cavazzuti Erica Malaguti Laura Cancian Prof. Giuseppe Paglietti (UISS) Dr. ebecca C. Wade (EML, EMBL) 9