Nigericin sodium salt

YCl₃•6H₂O and YbCl₃•6H₂O (both > 99.9%) were obtained from Treibacher Industrie AG. Oleic acid and 1-octadecene (both 90%) were from Alfa Aesar. NH₄F, ErCl₃•6H₂O (99.99%), NaOH, polyethylenimine (PEI) (branched, average M_w ∼ 25 kDa), and nitrosyl tetrafluoroborate (NOBF₄) (95%) were from Sigma-Aldrich.
The pHAb amine reactive dye was purchased from Promega. DMSO (99 + %) was from Alfa Aesar. Potassium chloride (99 + %) and sodium bicarbonate (99 + %) were from Acros Organics. Amine conjugation buffer was made by dissolving 0.084 g sodium bicarbonate in water, adjusting the pH to 8.5 using HCl/NaOH (100 mM), then adjusting the final volume to 100 mL with water. Citric acid monohydrate, disodium phosphate heptahydrate, and chlorpromazine hydrochloride (≥ 98%) were purchased from Sigma-Aldrich. All cell culture media were purchased from Thermo Fisher Scientific. Nigericin sodium salt was from Cayman Chemical. Cell Navigator green fluorescence, with 405 nm excitation, lysosome staining kit was purchased from AAT Bioquest. Nystatin was obtained from BioVision. The resazurin-based alamarBlue cell viability reagent and Trypan blue solution (0.4%) were purchased from Thermo Fisher Scientific. SH-SY5Y cells were obtained from the MRC Stem Cell Institute (University of Cambridge).

Actinomycin D (Sigma-Aldrich, A1410), actinomycin X2 (Adipogen, BVT-0375), antimycin A (Sigma-Aldrich, A8674), bafilomycin A1 (Cayman Chemical, 11038), bafilomycin B1 (Cayman Chemical, 14005), cycloheximide (ACROS Organics, AC357420010), filipin complex (Sigma-Aldrich, F9765), nigericin sodium salt (Cayman Chemical, 11437), nactins mixture (Cayman Chemical, 19468), novobiocin sodium salt (Calbiochem, 491207), piericidin A (Cayman Chemical, 15379), rubiginone B2 (Santa Cruz Biotechnology, sc-212793), and STA-21 (Sigma-Aldrich, SML2161).

The ReFRAME Library was accessed through CALIBR at Scripps Research. The covalent compound and the nucleoside mimetic libraries were purchased from ChemDiv. For follow-up assays, compounds identified from ChemDiv libraries were repurchased through ChemDiv. Ultrapure LPS, E. coli 0111:B4 (Invivogen; Cat. No. tlrl-3pelps) was dissolved in ultrapure water and administered at 1 ng/mL. MCC950 (SelleckChem; Cat. No. S7809) was dissolved in water and administered at 10 µM. Nigericin Sodium Salt (Cayman Chem.; Cat. No. 11437-25) was dissolved in ethanol and administered at 10 µM. All other compounds were dissolved in DMSO and sourced as listed in Supplementary Table 1.