Part:BBa_K2924026

α-s1-casein

The milk protein α-s1-casein from Bos taurus

Usage and Biology

α-s1-casein (CSN1S1), also named B5B3R8_BOVIN¹is a gene coding for a protein product and has the GeneID: 282208, which originates from ².

Caseins are among the most abundant proteins in native cow's milk. They are phosphoproteins and make up approximately 80% of total dairy protein mass. The milk proteins and their proportions are important to the parameters of milk manufacturing and the quality of milk protein. With a length of 17508 bp and 19 exons the bovine α-s1-casein gene is the most abundant one of the bovine caseins (12-15 g/L)³. The α-s1-casein protein may contain up to eight serine monophosphate residues, which cluster in a hydrophilic domain between amino acids 43–80 and, through modelling studies, are thought to be connected to a hydrophobic domain (amino acids 100–199) by helical and sheet secondary structures⁴. In the ability of milk to carry calcium phosphate, α-s1-casein also performs an significant part⁵.

The DNA sequence of the gene was acquired by reverse-translating the amino acid sequence. Further, in order to reach optimal heterologous expression in Escherichia coli the DNA sequence was designed with optimized codons and synthesized commercially.

Contribution

Team: PuiChing_Macau 2020
Summary: We have compared the original alpha-casein without adhesion domains and our engineered alpha casein with adhesion domains, by the fire retardancy test and added the RFP to the alpha casein in order to observe the adhesive test result under fluorescents microscope. As shown in Figures 1 & 2, it is significant that the protein with adhesion domain has a great improvement on its fire retardancy. In this figure, the results show a clear improvement of the adhesiveness of the fire retardant protein.

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Figure 1. Vertical Burning Test using bedsheet

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Figure 2. Fire retardant test for wood

Adhesion test

Figure 3. The adhesion level of (3b)K3503009(RFP-Alpha Casein), (3c)K3503011(RFP-mfp5-Alpha casein),(3d)K3503010 (RFP-CBD-Alpha casein) by different state of process(non- washing, after washing with water and soaking.)

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Figure 3(a) The percentage of the protein after processes

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Figure 3(b) K3503009(RFP-Alpha Casein)

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Figure 3(c) K3503011(RFP-mfp5-Alpha casein)

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Figure 3(d) K3503010 (RFP-CBD-Alpha casein)

Figure 3.The adhesion level of (3b)K3503009(RFP-Alpha Casein), (3c)K3503011(RFP-mfp5-Alpha casein),(3d)K3503010 (RFP-CBD-Alpha casein) by different state of process(non- washing, after washing with water and soaking.)

Conclusion

Overall, the proteins with adhesion retain a higher fire retardancy than the protein without adhesion through adhesive test and fire retardancy test. Therefore, the genetic fusion between alpha casein and adhesion domain would generate a more stable fire retardant protein.

</html> Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal BamHI site found at 643
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]

References

[1]: https://www.uniprot.org/uniprot/B5B3R8

[2]: https://www.ncbi.nlm.nih.gov/gene/?term=282208

[3]: Boland, Mike, Harjinder Singh, and Abby Thompson, eds. Milk proteins: from expression to food. Academic Press, 2014.

[4]: Sheehy, P. A., et al. "Significance, origin and function of bovine milk proteins: the biological implications of manipulation or modification." Milk Proteins. Academic Press, 2008. 81-106.

[5]: Chanat, E., J. Cell Sci., 112, 3399-3412 (1999)