Background:

TTNPB (Arotinoid Acid) is an agonist of RAR with IC50 values of 3.8nM, 4nM and 4.5nM for RARα, RARβ and RARγ, respectively [1].

TTNPB is a teratogen with 1000-fold higher potency than tRA. TTNPB inhibits chondrogenesis with IC50 value of 0.14nM when using mouse limb bud cell cultures. The action of TTNPB results from binding to nuclear receptors. TTNPB can competes with [3H]tRA and prevent them from binding to mRARα, mRARβ and mRARγ with IC50 values of 3.8nM, 4nM and 4.5nM, respectively. Besides that, TTNPB also directly binds to mRARs with high potency. The Kd values are 2.5nM, 2.7nM and 1.8nM for mRARα, mRARβ and mRARγ, respectively. Moreover, TTNPB is reported to bind to mCRABPI and mCRABPII with 27-fold and 3.5-fold lower affinity than tRA [1].

参考文献:
[1] Pignatello M A, Kauffman F C, Levin A A. Multiple factors contribute to the toxicity of the aromatic retinoid, TTNPB (Ro 13-7410): Binding affinities and disposition. Toxicology and applied pharmacology, 1997, 142(2): 319-327.