Stability of 20S Proteasome Configurations: Preopening the Axial Gate. Academic Article uri icon

abstract

  • Mass spectrometry studies of the stability of the S. cerevisiae 20S proteasome from 11 to 55 C reveal a series of related configurations and coupled transitions that appear to be associated with opening of the proteolytic core. We find no evidence for dissociation, and all transitions are reversible. A thermodynamic analysis indicates that configurations fall into three general types of structures: enthalpically stabilized, tightly closed (observed as the +54 to +58 charge states) configurations; high-entropy (+60 to +66) states that are proposed as precursors to pore opening; and larger (+70 to +79) partially and fully open pore structures. In the absence of the 19S regulatory unit, the mechanism for opening the 20S pore appears to involve a charge-priming process that loosens the closed-pore configuration. Only a small fraction (2%) of these 20S precursor configurations appear to open and thus expose the catalytic cavity.

published proceedings

  • J Phys Chem Lett

author list (cited authors)

  • Henderson, L. W., Sharon, E. M., Gautam, A., Anthony, A. J., Jarrold, M. F., Russell, D. H., Matouschek, A., & Clemmer, D. E.

citation count

  • 0

complete list of authors

  • Henderson, Lucas W||Sharon, Edie M||Gautam, Amit KS||Anthony, Adam J||Jarrold, Martin F||Russell, David H||Matouschek, Andreas||Clemmer, David E

publication date

  • June 2023