title: In vitro selection of a DNA-templated small-molecule library reveals a class of macrocyclic kinase inhibitors.
abstract: DNA-templated organic synthesis enables the translation of DNA sequences into synthetic small-molecule libraries suitable for in vitro selection. Previously, we described the DNA-templated multistep synthesis of a 13,824-membered small-molecule macrocycle library. Here, we report the discovery of small molecules that modulate the activity of kinase enzymes through the in vitro selection of this DNA-templated small-molecule macrocycle library against 36 biomedically relevant protein targets. DNA encoding selection survivors was amplified by PCR and identified by ultra-high-throughput DNA sequencing. Macrocycles corresponding to DNA sequences enriched upon selection against several protein kinases were synthesized on a multimilligram scale. In vitro assays revealed that these macrocycles inhibit (or activate) the kinases against which they were selected with IC(50) values as low as 680 nM. We characterized in depth a family of macrocycles enriched upon selection against Src kinase, and showed that inhibition was highly dependent on the identity of macrocycle building blocks as well as on backbone conformation. Two macrocycles in this family exhibited unusually strong Src inhibition selectivity even among kinases closely related to Src. One macrocycle was found to activate, rather than inhibit, its target kinase, VEGFR2. Taken together, these results establish the use of DNA-templated synthesis and in vitro selection to discover small molecules that modulate enzyme activities, and also reveal a new scaffold for selective ATP-competitive kinase inhibition.
authors.affiliation: Department of Chemistry and Chemical Biology and the Howard Hughes Medical Institute, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA.
authors.forename: Ralph E
authors.initials: RE
authors.lastname: Kleiner
authors.forename: Christoph E
authors.initials: CE
authors.lastname: Dumelin
authors.forename: Gerald C
authors.initials: GC
authors.lastname: Tiu
authors.forename: Kaori
authors.initials: K
authors.lastname: Sakurai
authors.forename: David R
authors.initials: DR
authors.lastname: Liu
mesh_terms: D004247:DNA / Q000737:chemistry*; D008968:Molecular Conformation; D047428:Protein Kinase Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D054852:Small Molecule Libraries / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D019061:src-Family Kinases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism
chemical_list: D047428:Protein Kinase Inhibitors; D054852:Small Molecule Libraries; D004247:DNA; D040301:Vascular Endothelial Growth Factor Receptor-2; D019061:src-Family Kinases