Design of a fluorescent ligand targeting the S-adenosylmethionine binding site of the histone methyltransferase MLL1. Issue 2 (6th November 2015)

• Record Type: Journal Article
• Authors: Luan, Yepeng; Blazer, Levi L.; Hu, Hao; Hajian, Taraneh; Zhang, Jing; Wu, Hong; Houliston, Scott; Arrowsmith, Cheryl H.; Vedadi, Masoud; Zheng, Yujun George
• Is Part Of: Organic & biomolecular chemistry. Volume 14:Issue 2(2016)
• Page Start: 631
• Page End: 638
• Publication Date: 2015-11-06
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/c5ob01794g
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : FL-NAH is a fluorescent ligand for the SAM-binding site of the MLL1 lysine methyltransferase. Abstract : The histone methyltransferase MLL1 has been linked to translocation-associated gene fusion in childhood leukemias and is an attractive drug target. High-throughput biochemical analysis of MLL1 methyltransferase activity requires the production of at least a trimeric complex of MLL1, RbBP5 and WDR5 to elicit robust activity. Production of trimeric and higher order MLL1 complexes in the quantities and reproducibility required for high-throughput screening presents a significant impediment to MLL1 drug discovery efforts. We present here a small molecule fluorescent ligand (FL-NAH, 6 ) that is able to bind to the S -adenosylmethionine (SAM) binding site of MLL1 in a manner independent of the associated complex members. We have used FL-NAH to develop a fluorescence polarization-based SAM displacement assay in a 384-well format targeting the MLL1 SET domain in the absence of associated complex members. FL-NAH competes with SAM and is displaced from the MLL1 SET domain by other SAM-binding site ligands with K disp values similar to the higher-order complexes, but is unaffected by the H3 peptide substrate. This assay enables screening for SAM-competitive MLL1 inhibitors without requiring the use of trimeric or higher order MLL1 complexes, significantly reducing screening time and cost.