Identification of the interaction region between hemagglutinin components of the botulinum toxin complex

Int J Biol Macromol. 2014 Apr:65:284-8. doi: 10.1016/j.ijbiomac.2014.01.052. Epub 2014 Jan 25.

Abstract

The large toxin complex (L-TC) produced by Clostridium botulinum is formed from the M-TC (BoNT/NTNHA complex) by conjugation of M-TC with HA-33/HA-17 trimer consists of two HA-33 proteins and a single HA-17 protein. This association is mediated by HA-70, which interacts with HA-17. The current study aims to identify the regions of the HA-70 molecule that adhere to the HA-33/HA-17 complex. Products from limited proteolysis of HA-70 were resolved by SDS-PAGE and transferred onto PVDF membranes, where they were probed with HA-33/HA-17 in a far-western blot. Among the HA-70 fragments, HA-33/HA-17 bound to those containing at least the C-terminal half of the HA-70 molecule, but not those carrying the N-terminal half. Additional docking simulation analysis indicated that the HA-70 region Gln420-Tyr575 is responsible for binding to HA-17, which is consistent with the far-western blot data. The findings here reveal additional details concerning the three-dimensional structure of the functional HA sub-complex in the botulinum toxin complex.

Keywords: Clostridium botulinum; Far-western blot; Hemagglutinin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Botulinum Toxins / chemistry*
  • Botulinum Toxins / metabolism*
  • Clostridium botulinum*
  • Hemagglutinins / chemistry*
  • Hemagglutinins / metabolism*
  • Membranes, Artificial
  • Molecular Docking Simulation
  • Polyvinyls / chemistry
  • Protein Binding
  • Protein Conformation

Substances

  • Hemagglutinins
  • Membranes, Artificial
  • Polyvinyls
  • polyvinylidene fluoride
  • Botulinum Toxins