@article{ReichBeckerSeckleretal.2009,
  author    = {Reich, Lothar and Becker, Marion and Seckler, Robert and Weikl, Thomas R.},
  title     = {In vivo folding efficiencies for mutants of the P22 tailspike beta-helix protein correlate with predicted stability changes},
  issn      = {0301-4622},
  doi       = {10.1016/j.bpc.2009.01.015},
  year      = {2009},
  abstract  = {Parallel A-helices are among the simplest repetitive structural elements in proteins. The folding behavior of A- helix proteins has been studied intensively, also to gain insight on the formation of amyloid fibrils, which share the parallel beta-helix as a central structural motif. An important system for investigating beta-helix folding is the tailspike protein from the Salmonella bacteriophage P22. The central domain of this protein is a right-handed parallel beta-helix with 13 windings. Extensive mutational analyses of the P22 tailspike protein have revealed two main phenotypes: temperature-sensitive-folding (tsf) mutations that reduce the folding efficiency at elevated temperatures, and global suppressor (su) mutations that increase the tailspike folding efficiency. A central question is whether these phenotypes can be understood from changes in the protein stability induced by the mutations. Experimental determination of the protein stability is complicated by the nearly irreversible trimerization of the folded tailspike protein. Here, we present calculations of stability changes with the program FoldX, focusing on a recently published extensive data set of 145 singe-residue alanine mutants. We find that the calculated stability changes are correlated with the experimentally measured in vivo folding efficiencies. In addition, we determine the free-energy landscape of the P22 tailspike protein in a nucleation-propagation model to explore the folding mechanism of this protein, and obtain a processive folding route on which the protein nucleates in the N-terminal region of the helix.},
  language  = {en}
}
@article{BarbirzBeckerFreibergetal.2009,
  author    = {Barbirz, Stefanie and Becker, Marion and Freiberg, Alexander and Seckler, Robert},
  title     = {Phage tailspike proteins with beta-solenoid fold as thermostable carbohydrate binding materials},
  issn      = {1616-5187},
  doi       = {10.1002/mabi.200800278},
  year      = {2009},
  abstract  = {We have investigated the stability of three tailspike proteins (TSPs) from bacteriophages Sf6, P22, and HK620. Tailspikes are rod-like homotrimers with comparable beta-solenoid folds and similarly high kinetic stability in spite of different amino acid sequences. As tailspikes bind polysaccharides to recognize the bacterial host cell, their stability is required for maintenance of bacteriophage infectivity under harsh extracellular conditions. They resist denaturation by SDS at ambient temperature and their unfolding is slow even in 6 m guanidinium hydrochloride (GdmHCl). This makes them interesting candidates for very stable carbohydrate binding protein materials.},
  language  = {en}
}