title: Chemical screening methods to identify ligands that promote protein stability, protein crystallization, and structure determination.
abstract: The 3D structures of human therapeutic targets are enabling for drug discovery. However, their purification and crystallization remain rate determining. In individual cases, ligands have been used to increase the success rate of protein purification and crystallization, but the broad applicability of this approach is unknown. We implemented two screening platforms, based on either fluorimetry or static light scattering, to measure the increase in protein thermal stability upon binding of a ligand without the need to monitor enzyme activity. In total, 221 different proteins from humans and human parasites were screened against one or both of two sorts of small-molecule libraries. The first library comprised different salts, pH conditions, and commonly found small molecules and was applicable to all proteins. The second comprised compounds specific for protein families of particular interest (e.g., protein kinases). In 20 cases, including nine unique human protein kinases, a small molecule was identified that stabilized the proteins and promoted structure determination. The methods are cost-effective, can be implemented in any laboratory, promise to increase the success rates of purifying and crystallizing human proteins significantly, and identify new ligands for these proteins.
authors.affiliation: Structural Genomics Consortium, University of Toronto, 100 College Street, Toronto, ON, Canada M5G 1L5.
authors.forename: Masoud
authors.initials: M
authors.lastname: Vedadi
authors.forename: Frank H
authors.initials: FH
authors.lastname: Niesen
authors.forename: Abdellah
authors.initials: A
authors.lastname: Allali-Hassani
authors.forename: Oleg Y
authors.initials: OY
authors.lastname: Fedorov
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Finerty
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Wasney
authors.forename: Ron
authors.initials: R
authors.lastname: Yeung
authors.forename: Cheryl
authors.initials: C
authors.lastname: Arrowsmith
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Ball
authors.forename: Helena
authors.initials: H
authors.lastname: Berglund
authors.forename: Raymond
authors.initials: R
authors.lastname: Hui
authors.forename: Brian D
authors.initials: BD
authors.lastname: Marsden
authors.forename: Pär
authors.initials: P
authors.lastname: Nordlund
authors.forename: Michael
authors.initials: M
authors.lastname: Sundstrom
authors.forename: Johan
authors.initials: J
authors.lastname: Weigelt
authors.forename: Aled M
authors.initials: AM
authors.lastname: Edwards
mesh_terms: D000818:Animals; D019295:Computational Biology; D003460:Crystallization; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D006801:Humans; D008024:Ligands; D011485:Protein Binding; D011487:Protein Conformation; D011489:Protein Denaturation; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism*; D013696:Temperature; D013816:Thermodynamics
chemical_list: D008024:Ligands; D011506:Proteins