We identifyied AR and SUMO2/3 chromatomes in castration-resistant prostate cancer cells (VCaP) and studied the impact on SUMOylation inhibition (SUMOi)on them utilizing small molecule inhibitor ML792. Chromatome members were identifyied with Rapid Immunoprecipitation Mass spectrometry of Endogenous proteins (RIME) in absence and presence of androgen and ML792. Mass spectrometry analyses were executed with high resolution mass spectrometry LC-MS analysis was performed by using the Evosep One liquid chromatography system coupled to a hybrid trapped ion mobility quadrupole TOF mass spectrometer (Bruker timsTOF Pro) via a CaptiveSpray nano-electrospray ion source. High-confidence chromatome members discriminated from background with SAINT analysis.