Part:BBa_K1621005

TpF1 - bacterioferritin derived from Treponema pallidum

This part contains the coding sequence of a bacterioferritin monomer derived from Treponema pallidum, TpF1. It was isolated from the subspecies pallidum which causes syphilis, a disease that is transmittable by sexual contact or congenitally. Worldwide, more than 12 million new cases of syphilis are reported, which underlines the need of detection methods that are highly sensitive and specific as well as easy to perform.

TpF1 was shown to be highly immunogenic in humans and rabbits (McGill et al., 2010), which was the reason for Jiang et al. (2013) to use it for the establishment of a diagnostic ELISA for clinical applications.

Bacterioferritins in general are central players in bacterial iron metabolism. Their functions reach from detoxification of iron in the cell to iron storage and even protection against oxidative stress (Carrondo 2003). Disuflide bonds and hydrophobic interactions mediate the formation of homo-24-mers of about 190 kDa in the outer membrane (Radolf et al. 1987). Treatment with β-mercaptoethanol or boiling in SDS leads to dissaggregation of the complex, resulting in smaller oligomers (~160 kDa) and monomers (~19 kDa). This part’s sequence encodes for such a monomer (Jiang et al. 2013).

The sequence was synthesized by Integrated DNA Technologies in a variant that was codon optimized for expression in Escherichia coli with the respective tool from IDT. It was shipped to the Registry in standard pSB1C3 and begins with a start codon (ATG). Cloning into the shipping backbone was performed by Gibson Assembly.

References

McGill MA, Edmondson DG, Carroll JA, Cook RG, Orkiszewski RS, Norris SJ, Characterization and serologic analysis of the Treponema pallidum proteome (2010). Infect. Immun. 78:2631–2643.

Radolf JD, Borenstein LA, Kim JY, Fehniger TE, Lovett MA, Role of disulfide bonds in the oligomeric structure and protease resistance of recombinant and native Treponema pallidum surface antigen 4D (1987). J Bacteriol. 169(4):1365-71.

Carrondo MA, Ferritins, iron uptake and storage from the bacterioferritin viewpoint (2003). EMBO J. 22(9):1959-68.