Structure-Based Design of a Novel Class of Autotaxin InhibitorsBased on Endogenous Allosteric Modulators

Autotaxin (ATX) facilitates the hydrolysis of lysophosphatidylcholine to lysophosphatidic acid (LPA), a bioactivephospholipid, which facilitates a diverse range of cellular effects in multiple tissue types. Abnormal LPA expression can lead to theprogression of diseases such as cancer andfibrosis. Previously, we identified a potent ATX steroid-derived hybrid (partiallyorthosteric and allosteric) inhibitor which did not form interactions with the catalytic site. Herein, we describe the design, synthesis,and biological evaluation of a focused library of novel steroid-derived analogues targeting the bimetallic catalytic site, representing anentirely unique class of ATX inhibitors of type V designation, which demonstrate significant pathway-relevant biochemical andphenotypic biological effects. The current compounds modulated LPA-mediated ATX allostery and achieved indirect blockage ofLPA1internalization, in line with the observed reduction in downstream signaling cascades and chemotaxis induction. These noveltype V ATX inhibitors represent a promising tool to inactivate the ATX-LPA signaling axis.