Part:BBa_K3561001

Pd4 (Pacardo et al., 2009)

Pd4 is a palladium binding peptide. It is used as a library peptide in our project to act as a template for our mutations. The results of molecular dynamics for our modified peptides are also compared with this peptide. This peptide has an isoelectric point of 11.1, a molecular weight of 1.35 kDa and hydrophobicity of 21.38. The histidine residues at positions 6 and 11 are reported to bind to palladium and arginine is reported to coordinate with palladium in the literature of which the peptide is discovered(Pacardo et al., 2009). The serine and threonine residues at positions 1 and 2 are also reported to be important in binding with palladium(Sarikaya et al., 2003). The amino acid sequence is TSNAVHPTLRHL.

References

Pacardo, et al. “Biomimetic Synthesis of Pd Nanocatalysts for the Stille Coupling Reaction.” ACS Nano, U.S. National Library of Medicine, 2009, pubmed.ncbi.nlm.nih.gov/19422199/.

Sarikaya et al. “Molecular Biomimetics: Nanotechnology through Biology.” Nature News, Nature Publishing Group, 2003, www.nature.com/articles/nmat964.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]

Modelling

From our molecular dynamics, we were able to determine the distance of the peptide from the palladium ion, the radius of gyration, the RMSD score and the total energy of the system.

We can compare the bond lengths of our peptides with the distances reported by previous literature to evaluate the attraction between the palladium ion and the peptide. The distance should also stay consistent.

The radius of gyration represent the compactness of the peptide, the peptide is generally more stable if the standard deviation is smaller. RMSD measures the average distance each atom deviated from the start of the simulation. A small deviation in RMSD indicates a stable structure.

We have also evaluated the total energy of the system during the simulation, if the total energy of the system varies a lot, it indicates that the law of energy conservation has not been fulfilled and further in vitro analysis is required to prove its reducing ability.

More details of how our molecular dynamics is run can be found on our team wiki.