Structure of a de novo designed protein model of radical enzymes. Academic Article uri icon

abstract

  • The use of side chains as catalytic cofactors for protein mediated redox chemistry raises significant mechanistic issues as to how these amino acids are activated toward radical chemistry in a controlled manner. De novo protein design has been used to examine the structural basis for the creation and maintenance of a tryptophanyl radical in a three-helix bundle protein maquette. Here we report the detailed structural analysis of the protein by multidimensional NMR methods. An interesting feature of the structure is an apparent pi-cation interaction involving the sole tryptophan and a lysine side chain. Hybrid density functional calculations support the notion that this interaction raises the reduction potential of the W degrees /WH redox pair and helps explain the redox characteristics of the protein. This model protein system therefore provides a powerful model for exploring the structural basis for controlled radical chemistry in protein.

published proceedings

  • J Am Chem Soc

author list (cited authors)

  • Dai, Q., Tommos, C., Fuentes, E. J., Blomberg, M., Dutton, P. L., & Wand, A. J.

citation count

  • 64

complete list of authors

  • Dai, Qing-Hong||Tommos, Cecilia||Fuentes, Ernesto J||Blomberg, Margareta RA||Dutton, P Leslie||Wand, A Joshua

publication date

  • September 2002