Part:BBa_K3561015

W9A6C11

This peptide is expected to be a palladium reducing peptide. This peptide is modified by our team from the palladium binding peptide A6C11 (Coppage et al., 2013). We have incorporated a tryptophan residue at position 9 into the peptide as it was reported that tryptophan is capable of reducing palladium (Chiu et al., 2010). We did not use a double tryptophan structure in this peptide. This can enable a comparison of palladium reducing efficiency between single tryptophan and double tryptophan structures. Thus, we can evaluate whether a double tryptophan will be more effective in palladium reducing. We also want to investigate what effects will there have if we inserted the tryptophan residue at different positions.

This peptide has an isoelectric point of 9.0, a molecular weight of 1.31 kDa and hydrophobicity of 26.32. The alanine residue at positions 4 and 6 has a minimal binding with palladium while the cysteine residue at position 11 has a strong binding with palladium, it was suggested that this may have higher efficiency(Coppage et al., 2013). The serine residue at position 2 and threonine at position 10 is also reported to be important in binding with palladium(Sarikaya et al., 2003). The amino acid sequence of the peptide is TSNAVAPTWRCL.

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.

Coppage, et al. “Exploiting Localized Surface Binding Effects to Enhance the Catalytic Reactivity of Peptide-Capped Nanoparticles.” Journal of the American Chemical Society, U.S. National Library of Medicine, 2013, pubmed.ncbi.nlm.nih.gov/23865951/.

Chiu, et al. Size-Controlled Synthesis of Pd Nanocrystals Using a Specific Multifunctional Peptide. 2010, pubmed.ncbi.nlm.nih.gov/20648291/.

DI;, Tan YN;Lee JY;Wang. Uncovering the Design Rules for Peptide Synthesis of Metal Nanoparticles. 2010, pubmed.ncbi.nlm.nih.gov/20355728/.

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.