Fluorescence Polarization Screening Assays for Small Molecule Allosteric Modulators of ABL Kinase Function
A) Sequences of the ABL SH3 binding peptides, p41, p40, p8, and 3BP-1, and their published binding affinities for the ABL SH3 domain [20,21]. Sequences of the wild type (WT) and high-affinity (HAL) SH2-kinase linker sequences are also shown at the bottom. The peptide sequences are presented in the C- to N-terminal orientation to align with those of the linkers. B) Crystal structure of the p41 peptide (cyan) bound to the ABL SH3 domain (PDB: 1BBZ) . The SH3 surface is shown as a space filling model (red) and side chains of residues that interact with the p41 peptide are shown as sticks. C) Crystal structure of the SH2-kinase linker (orange) bound to the ABL SH3 domain (red) from the ABL core (PDB: 2FO0) . Side chains of SH3 domain residues that interact with the p41 peptide as per panel B are shown as sticks. Note the lack of hydrophobic interactions and hydrogen bonds between the SH3 domain and the linker in comparison to the p41 peptide.