Only MS quality organic solvents were used during sample preparation. Samples were CHCl3/MeOH precipitated, resuspended in 1% Rapigest, diluted in 50 mM HEPES pH 8.0, reducing 30 min. with 5 mM TCEP, alkylated for 30 min in the dark with 10 mM iodoacetamide, digested with 500 ng trypsin overnight at 600 rpm and 27 °C, labeled with the appropriate TMT tag NHS-ester in 40% acetonitrile for 1 h, quenched with ammonium bicarbonate, pooled, acidified by being brought to 5% formic acid, and clarified by centrifugation for 30 min. at 21000 x g. The composition for buffer A is 0.1% formic acid, 5% acetonitrile in water. The composition for Buffer B is 0.1% formic acid, 80% acetonitrile in water. The composition for Buffer C is 500 mM ammonium acetate in Buffer A. MS runs were performed by using a two-dimensional LC/MS/MS setup on an LTQ Orbitrap Velos Pro hybrid mass spectrometer (Thermo) interfaced with an Easy-nLC 1000 (Thermo) according to standard MuDPIT protocols . For each run, MS/MS spectra were extracted using MSConvert (version 3.0.21144) with Peak Picking Filtering. FragPipe was used to search MS/MS spectra against a Uniprot human proteome database (06/11/2021 release, longest entry for each protein) supplemented with common contaminants and reverse sequence decoys for a total of 40858 sequences . MS/MS spectra were also searched against 20429 select decoys (e.g albumen, porcine trypsin, contaminants etc.). FragPipe searches allowed for static modification of cysteine residues (57.02146 Da, acetylation), variable modifications of herbicide adducts (175.0997 for propachlor adducts, 233.1416 for acetochlor and alachlor adducts), static TMT taggin of N-termini and lysine residues (229.1629 Da), and half tryptic peptidolysis specificity. We allowed a mass tolerance of 1.25 Da for the precursor ion mass and 20 ppm for the product ion masses. MSFragger (Version 3.2) was used to match and filter spectra. Decoy proteins, common contaminants, immunoglobulins, and keratins were filtered from the final protein list. Quantitation in FragPipe was performed by averaging TMT reporter ion intensities for all spectra associated with an individual peptide. Raw proteomics data is available through the PRIDE Archive at PXD030635. Flag GAPDH AP-MS was performed similarly, except digestion was performed using two step LysC/Trypsin (Promega) digestion according to manufacturer's protocol, and dynamic exclusion was set to 30 seconds during LC-MS/MS analysis of peptides. Open search was performed in FragPipe using default settings . For intact protein MS, beads were washed 4 times with PBS after RIPA washes and eluted overnight in 8.8 M urea in 50 mM Tris pH 8.0. Quantitative immunodepletion was confirmed by immunoblotting, sample purity was confirmed by SDS-PAGE followed by silver stain, and samples were analyzed by LC-ESI-MS on an Agilent 6545 LC/QTOF. Charge state envelopes were deconvoluted using MassHunter Bioconfirm software.