Page 71 - I. Chemical biology and drug discovery

Development of reversible covalent PPARγ

antagonistic ligands based on a structure-

based approach

Hyunsoo Kim¹, Jun Young Jang², Byung Woo Han², Seung Bum Park¹*
,
¹Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea,
²Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826,
Republic of Korea

ABSTRACT
In this study, we developed a novel reversible covalent PPARγ ligand and demonstrated its antidiabetic
activity in in vitro and in vivo systems. Also, we elucidated the structural basis for the inhibitory effects
of a reversible covalent ligand on PPARγ phosphorylation by X-ray crystallography study. Based on the
crystal structure of PPARγ, we rationally designed and synthesized a series of covalent inhibitor
analogues to develop selective PPARγ phosphorylation inhibitors. As a result, we developed SB1495,
novel reversible covalent inhibitor of PPARγ phosphorylation without classical transactivation. The
antidiabetic effect of SB1495 was demonstrated in the cellular system as well as in the mouse model. We
also observed the covalent anchoring of SB1495 on Cys313 at the ligand-binding pocket of PPARγ by X-
ray crystallography.
Introduction Rational design and synthesis

► Co-crystal structure of
SB1453–hPPARγ LBD. hPPARγ
LBD is shown as ribbon, Tyr473
and SB1453 are shown as sticks.
SB1453 is colored in orange.
► Design strategy of two
different covalent PPARγ ligands
Biological evaluation X-ray co-crystal structure
(a) (b)
(a) Structure of SB1495
(b) In vitro PPARγ
phosphorylation assay
(c) upon treatment with
Rosi and SB1495
(c) Oil Red O staining of
(d) accumulated lipid droplets
in 3T3-L1 adipocytes
upon treatment with
rosiglitazone or SB1495 ► Covalent binding modes
(d) Inhibitory activity of SB1495 in in the SB1495-bound and
PPARγ phosphorylation of 3T3-L1 PPARγ LBD structures.
(e) (f) adipocytes (e) mRNA transcriptional Blue shade indicated
profiles of the agonistic gene set specific hydrophobic region
regulated by PPARγ phosphorylation in related to phosphorylation
3T3-L1 adipocytes (f) Glucose-tolerance inhibition
test in diet-induced obese (DIO) mice
upon intraperitoneal administration of
either vehicle or SB1495 Asian J . Org. Chem. 2019, 8, 1698–1706
Scientific reports 2019, 9, 11168