Coding

Part:BBa_K925005

Designed by: Michael Paul Lockhart   Group: iGEM12_St_Andrews   (2012-09-24)

PdTagGST

This part produces functioning glutathione S-transferase (GST) protein that has a short petide sequence that binds palladium attached to the end of it. This allows the part to function as a palladium scavenger as the GST end can be bound to GST beads, while the palladium binding end is free to bind to any free Pd in solution.

Sequence and Features


Assembly Compatibility:
  • 10
    INCOMPATIBLE WITH RFC[10]
    Illegal PstI site found at 292
  • 12
    INCOMPATIBLE WITH RFC[12]
    Illegal PstI site found at 292
  • 21
    COMPATIBLE WITH RFC[21]
  • 23
    INCOMPATIBLE WITH RFC[23]
    Illegal PstI site found at 292
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal PstI site found at 292
  • 1000
    COMPATIBLE WITH RFC[1000]


Description

This part was designed to provide a practical means for palladium scavenging. The GST end of the protein would be bound to beads and the palladium end free and able to bind. This would allow aqueous solution to be passed down a collum of GST beads with any free palladium being bound to the double ended protein.

Characterisation

No characterisation was undertaken.

Results

No results have been found.

Conclusion

This part has been designed and ligated but no expression or characterisation work has been done.

Contribution

Group: HK_SSC, 2020
Author: Huang Helene Heling

Background

IGEM team 2012 St_Andrews designed a peptide with Pd binding properties. However, no characterisation was carried out. Our team decided to carry out an in silico simulation to predict the peptide’s functionality and evaluate its stability. Method The structure of the Pd binding peptide designed by St Andrews was predicted by using I-TASSER. Protein was solvated in water model spc216. The Molecular Dynamics simulation was performed using GROMACS 2020.3. MD results The interaction between the peptide and Pd was analysed through 4 aspects.

BBa K925005- Contribution Distance.jpg
The distance of the O in hydroxyl group between threonine and Pd were evaluated for 80ns. The average and standard deviation of the distance were 2.286150981nm and 0.45291467nm respectively.

BBa K925005-Contribution RMSD.jpg

The root mean square deviation (RMSD) of peptide backbone atoms measures the structure of the peptide throughout the simulation. The average and standard deviation of the RMSD were 0.2429242nm and 0.036509137nm respectively. The small RMSD shows that the peptide was stable.


 BBa K925005-Contribution Gyration.jpg

Radius of gyration (Rg) measures the compactness of the protein structure. The average and standard deviation of the Rg were 1.867476428nm and 0.015650297nm respectively.

 BBa K925005-Contribution Energy.jpg

Total energy of the system showed conservation of energy. The average and standard deviation of the total energy were -808423.6426 KJ/mol and 1443.8496 KJ/mol respectively.

Conclusion

The PdTagGST consists of a glutathione S-transferase protein, in which the molecular size (24.35 kilodaltons) is relatively larger than that of the palladium peptide (0.84 kilodaltons) proposed by St_Andrews. The intermolecular force between the Pd (II) ions and the Pd peptide may be weakened, as the larger sized GST may exhibit a stronger molecular interaction with Pd (II) ions. Therefore, the distance between the expected binding residue, threonine, and the Pd (II) ions was larger than expected. Further in vitro analysis is required to prove the binding ability of this part.

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Parameters
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