Part:BBa_K2043015

GFP-FBD8

Introduction

This part corresponds to the GFP genes bound to the Fabric Binding Domain 8 (FBD8). In the context of Paris Bettencourt 2016 iGEM project, Frank&Stain, we looked for novel fabric binding domains with phage display technique in order to optimise enzymes by fusing them with different FBD.
Results from our models suggest that the addition of FBD with optimal affinity can concentrate an enzyme near the fabric surface and therefore increase stain-degrading enzymatic activity. Using the method of phage display, we isolated 40 short peptides with affinity for cotton, linen, wool, polyester or silk. Bioinformatic analysis identified sequence motifs and biophysical features associated with binding to each fabric, or nonspecific binding to several fabrics. Several peptides were selected for further analysis by quantitative ELISA. The peptides discovered were used to fuse with GFP and stain-degrading enzymes to target wine-stained fabric samples.
The peptides are identified by in vitro phage-display screening of libraries containing typically 10⁹ distinct, linear 7 amino-acid peptides against our target, in our case different fabrics- cotton, wool, silk, linen, polyester, and the library is enriched with the phages which binds to the fabric over several rounds of panning.

Table 1 Characteristics of Fabric Binding Domain. The numbers next to each fabric means the number of times the sequence was repeated in each fabric

Name	Amino Acid Sequence	Binding Affinity	Charge	Hydropathicity
FBD8	QFPPPPG	Specific to linen: Cotton(0), Linen(1), Polyester(0), Silk(0), Wool(0)	0	-1.071

Testing the part

ELISA for each FBD incubated with each fabric after two rounds of washing, normalized to the level after a single round. In figure 1 we see that FBD7 binds only to Cotton and nylon with around 60% affinity


Figure 1 Fabric binding domain validation by ELISA. Control matrix repeating the procedure of panel A without phage.

In this figure we can see that when it is fused to the phage, the FBD8 binds to only Cotton, Linen and Silk with around 75%, 99% and 95% respectively.

Figure 2 Bar plot showing the fluorescence of cell extracts relative to the control (No GFP expressed). Here we compare the fluorescence of different cell extract expressing Fabric Binding Domains (FBDs) with affinity for different fabrics. The part BBa_K1321357 (GFP-CBDex) was used as positive control. The blue bar correspond with the negative control (no GFP in the cell extract) whereas the green ones with those whose fluorescence was higher than the control and in red those which presented no fluorescence, maybe because lacking activity or functionality.

Unfortunately, according with the figure 2 we couldn’t express properly this fusion protein with GFP, or maybe it affects the activity of GFP and therefore we couldn’t see the fluorescence.

References

Berglund, J., Lindbladh, C., Mosbach, K., & Nicholls, I. A. (1998). Selection of phage display combinatorial library peptides with affinity for a yohimbine imprinted methacrylate polymer. Analytical Communications, 35(1), 3-7.

Boyer, S., Biswas, D., Soshee, A. K., Scaramozzino, N., Nizak, C., & Rivoire, O. (2016). Hierarchy and extremes in selections from pools of randomized proteins. Proceedings of the National Academy of Sciences, 201517813.

Devlin, J. J., Panganiban, L. C., & Devlin, P. E. (1990). Random peptide libraries: a source of specific protein binding molecules. Science, 249(4967), 404-406.

Goncalves, V., Gautier, B., Garbay, C., Vidal, M., & Inguimbert, N. (2007). Development of a chemiluminescent screening assay for detection of vascular endothelial growth factor receptor 1 ligands. Analytical biochemistry, 366(1), 108-110.

Günay, K. A., & Klok, H. A. (2015). Identification of Soft Matter Binding Peptide Ligands Using Phage Display. Bioconjugate chemistry, 26(10), 2002-2015.

Hoogenboom, H. R., Griffiths, A. D., Johnson, K. S., Chiswell, D. J., Hudson, P., & Winter, G. (1991). Multi-subunit proteins on the surface of filamentous phage: methodologies for displaying antibody (Fab) heavy and light chains. Nucleic acids research, 19(15), 4133-4137.

Jain, P., Soshee, A., Narayanan, S. S., Sharma, J., Girard, C., Dujardin, E., & Nizak, C. (2014). Selection of arginine-rich anti-gold antibodies engineered for plasmonic colloid self-assembly. The Journal of Physical Chemistry C, 118(26), 14502-14510.

Matsuura, K., Ueno, G., & Fujita, S. (2015). Self-assembled artificial viral capsid decorated with gold nanoparticles. Polymer Journal, 47(2), 146-151.

Soshee, A., Zürcher, S., Spencer, N. D., Halperin, A., & Nizak, C. (2013). General in vitro method to analyze the interactions of synthetic polymers with human antibody repertoires. Biomacromolecules, 15(1), 113-121.

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]