1：Experimental Design and Method Selection:

The study involved synthesizing two novel photoswitchable amino acids (Fmoc-cAzoAA and Mtt-oF4AzoAA) based on azobenzene derivatives, incorporating them into peptide backbones via Fmoc solid-phase peptide synthesis or solution-phase ligation, and evaluating their photochemical properties, binding affinities to WDR5, and inhibition of MLL1 activity using fluorescence polarization assays, AlphaLISA HMT assays, GST pull-down assays, crystallography, and molecular dynamics simulations.

2：Sample Selection and Data Sources:

Peptidomimetics were designed as analogues of a previous AMPB-containing peptide, with samples prepared in aqueous solutions for UV-vis spectroscopy, HPLC, NMR, and biological assays using recombinant proteins and peptides.

3：List of Experimental Equipment and Materials:

Equipment included a Bruker AV III HD NMR spectrometer, LTQ-FT Ultra mass spectrometer, Tecan Spark 20M microplate reader, Perkin Elmer EnVision plate reader, LED lamps for irradiation, HPLC systems, and crystallography facilities at ESRF. Materials included commercial reagents, solvents, peptides, proteins (e.g., WDR5, MLL1), and chemicals for synthesis and assays.

4：Experimental Procedures and Operational Workflow:

Synthesis of building blocks, peptide incorporation, photoisomerization studies with UV-vis and HPLC, binding assays with fluorescence polarization, enzymatic inhibition assays with AlphaLISA, GST pull-down experiments, crystallization of protein-ligand complexes, data collection, structure determination, molecular docking with GOLD software, and molecular dynamics simulations with GROMACS.

5：Data Analysis Methods:

Data were analyzed using UV-vis spectroscopy for isomer ratios, HPLC and NMR for purity and conversion, fluorescence polarization for Ki values, AlphaLISA for IC50 values, crystallography with XDS and PHENIX for structure refinement, and MM/PBSA for binding energy calculations from MD simulations.