Get Phases from Arsenic Anomalous Scattering: de novo SAD Phasing of Two Protein Structures Crystallized in Cacodylate Buffer
2011

Using Arsenic to Solve Protein Structures

publication Evidence: moderate

Author Information

Author(s): Liu Xiang, Zhang Heng, Xiao-Jun Li, Lan-Fen Su, Xiao-Dong

Primary Institution: State Key Laboratory of Protein and Plant Gene Research and Biodynamic Optical Imaging Center (BIOPIC), School of Life Sciences, Peking University, Beijing, China

Hypothesis

Can arsenic be effectively used as an anomalous scatterer in SAD phasing for protein crystallography?

Conclusion

The study demonstrates that arsenic can serve as an ideal anomalous scatterer for SAD phasing in protein crystallography.

Supporting Evidence

  • Arsenic was covalently introduced into proteins by cacodylic acid during crystallization.
  • The study successfully solved the structures of a putative pyrazinamidase from Streptococcus mutans and human caspase-6 using arsenic.
  • Arsenic showed higher phasing power compared to zinc in the studied proteins.

Takeaway

This study shows that arsenic can help scientists figure out the shapes of proteins, which is important for understanding how they work.

Methodology

The study used de novo arsenic single-wavelength anomalous diffraction (As-SAD) phasing method to solve the crystal structures of two proteins.

Limitations

The use of arsenic is limited by its toxicity and the lack of general protocols for its incorporation into proteins.

Digital Object Identifier (DOI)

10.1371/journal.pone.0024227

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