Expression, fermentation and purification of a predicted intrinsically disordered region of the transcription factor, NFAT5

•Construct pET-MBP-872-1271 was expressed in E. coli and grown through fermentation.•Specific AcTEV cleavage followed by His-tag affinity further purified 872-1271.•Continued purification with a DEAE and HIC columns completed purification of 872-1271.•Concentrated to 0.2mg/mL; sufficient to study intrinsic disorder using fluorescence.•Protein mass confirmed with HPLC–MS.