1B-O1-1500 PDF
Factors causing the structural variety of histone H2A/H2B dimer in the gas phase
The histone H2A/H2B dimer, a component of nucleosome core particle (NCP), has three intrinsically disordered tail regions. We have characterized gas-phase behaviors of these functionally important disordered regions associated with the folded core part. We have prepared not only wild-type histone H2A/H2B dimer but also the mutant dimers, in which most parts of N- and/or C-terminal tail regions were deleted, and analyzed them by electrospray ionization (ESI) ion mobility mass spectrometry (IM-MS). By IM-MS, two populations in size were clearly recognized for the wild-type dimer, while the mutant with extremely short tails showed a slight structural diversity. In addition, we investigated the effects of two factors, instrumental parameters and positive charges in the tail regions, on the structural variety. It was found that only flexible tail regions became unstable upon introduction into the mobility cell, regardless of the charge density of the tail regions.