Structure-Based Virtual Screening Protocol for in Silico Identification of Potential Thyroid Disrupting Chemicals Targeting Transthyretin.
Thyroid disruption by xenobiotics is associated with a broad spectrum of severe adverse outcomes. One possible molecular target of thyroid hormone disrupting chemicals (THDCs) is transthyretin (TTR), a thyroid hormone transporter in vertebrates. To better understand the interactions between TTR and THDCs, we determined the crystallographic structures of human TTR in complex with perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and 2,2',4,4'-tetrahydroxybenzophenone (BP2). The molecular interactions between the ligands and TTR were further characterized using molecular dynamics simulations. A structure-based virtual screening (VS) protocol was developed with the intention of providing an efficient tool for the discovery of novel TTR-binders from the Tox21 inventory. Among the 192 predicted binders, 12 representatives were selected, and their TTR binding affinities were studied with isothermal titration calorimetry, of which seven compounds had binding affinities between 0.26 and 100 μM. To elucidate structural details in their binding to TTR, crystal structures were determined of TTR in complex with four of the identified compounds including 2,6-dinitro-p-cresol, bisphenol S, clonixin, and triclopyr. The compounds were found to bind in the TTR hormone binding sites as predicted. Our results show that the developed VS protocol is able to successfully identify potential THDCs, and we suggest that it can be used to propose THDCs for future toxicological evaluations.
Department of Chemistry and ‡Department of Medical Biochemistry and Biophysics, Umeå University , SE-901 87 Umeå, Sweden.
Jin
J
Zhang
Department of Chemistry and ‡Department of Medical Biochemistry and Biophysics, Umeå University , SE-901 87 Umeå, Sweden.
Afshan
A
Begum
Department of Chemistry and ‡Department of Medical Biochemistry and Biophysics, Umeå University , SE-901 87 Umeå, Sweden.
Kristoffer
K
Brännström
Department of Chemistry and ‡Department of Medical Biochemistry and Biophysics, Umeå University , SE-901 87 Umeå, Sweden.
Christin
C
Grundström
Department of Chemistry and ‡Department of Medical Biochemistry and Biophysics, Umeå University , SE-901 87 Umeå, Sweden.
Irina
I
Iakovleva
Department of Chemistry and ‡Department of Medical Biochemistry and Biophysics, Umeå University , SE-901 87 Umeå, Sweden.
Anders
A
Olofsson
Department of Chemistry and ‡Department of Medical Biochemistry and Biophysics, Umeå University , SE-901 87 Umeå, Sweden.
A Elisabeth
AE
Sauer-Eriksson
Department of Chemistry and ‡Department of Medical Biochemistry and Biophysics, Umeå University , SE-901 87 Umeå, Sweden.
Patrik L
PL
Andersson
D000818:Animals; D001665:Binding Sites; D003198:Computer Simulation; D006801:Humans; D011228:Prealbumin / Q000378:metabolism*; D013961:Thyroid Gland / Q000378:metabolism*; D013963:Thyroid Hormones / Q000378:metabolism
D011228:Prealbumin; D013963:Thyroid Hormones