Partial trypsin digestion analyses of free HDAC3(1–428), DAD-bound HDAC3(1–428) and free HDAC3(1-411).A, a diagram showing that trypsin digests HDAC3 at N- and C-terminal sites. The generated N-terminus-containing fragments (N1 and N2) were detected by the anti-HDAC3 N-terminus antibody (N-19). A C-terminus-containing fragment (C1) was detected by the anti-FLAG antibody via the C-terminus-fused FLAG tag. B, trypsin digestion of free HDAC3 and HDAC3/DAD complex. C, trypsin cleavage of free HDAC3(1–428) and HDAC3(1–411). The bottom shows NIH-Image J-quantified ratios of N1 versus N2, N1 versus the remaining uncut sample, or C1 versus the remaining uncut sample.