Sample preparation for top–down MS Stable SIRT2 KD HEK293T cells were seeded in 20 15-cm plates to 50% confluency. Twenty-four hours later, each plate was transfected with 10 μg of ARF6-3XFlag (pJaff211 plasmid) and 5 μg of HA-NMT2. Twenty-four hours later, the cells wer...