Favourable mediation of crystal contacts by cocoamidopropylbetaine (CAPB)

Acta Crystallogr D Biol Crystallogr. 2005 Apr;61(Pt 4):477-80. doi: 10.1107/S0907444905001204. Epub 2005 Mar 24.

Abstract

Crystals of excellent quality are a prerequisite for high-resolution X-ray data. However, in refinement protocols of crystallization conditions it is often difficult to obtain the right combination of, for example, protein concentration, drop size, temperature and additives. A novel approach for optimizing crystal contacts in a most favourable fashion by performing crystallization setups with the zwitterionic surfactant cocoamidoproylbetaine (CAPB) is introduced. In the presence of this surfactant, highly diffracting crystals were obtained. Here, data from a right-handed coiled coil (RHCC) in complex with CAPB at 1.4 A resolution are presented. The addition of CAPB using otherwise identical crystallization conditions and the same X-ray source caused an improvement in resolution from 2.9 to 1.4 A.

MeSH terms

  • Archaeal Proteins / chemistry*
  • Betaine / analogs & derivatives*
  • Betaine / chemistry
  • Crystallization / methods*
  • Models, Molecular
  • Protein Structure, Tertiary
  • Surface-Active Agents / chemistry*
  • X-Ray Diffraction / methods

Substances

  • Archaeal Proteins
  • Surface-Active Agents
  • cocoamidopropylbetaine
  • Betaine