Part:BBa_K4607008

PCNP

Description

The biobrick consists of the polycationic nonapeptide (PCNP) which is capable to destabilize the lipopolysaccharide binds on Gram-negative baterium. The principle about the PCNP is related to the ionic interactions between the phosphate groups, divalent cations, and hyrdophobic lipids' stacking, where the PCNP acts as a destabilizing. This part has been fused with endolysins in order to increase their capability to lyse Gram-negative bacterium, demonstrating that the addition of the PCNP allows the endolysin introduction into the bacteria cell membrane. It part have been evaluated in Escherichia coli. The peptide has a lenght of nine amino acids [1].

imagen Figure 1. PCNP diagram.

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]

Usage and Biology

As a brief contextualization, bovine mastitis is the result of the infection of the bovine mammary glands caused by pathogenic microorganisms, mainly gram-positive and negative bacteria. This disease reduces milk quality production to a great extent and produces painful damage to the bovine. The main treatment for mastitis is the use of diverse antibiotics, therefore the overuse and misuse of them have caused a real problem in the development of multidrug-resistant pathogens [2]. Our team has conducted an extensive investigation to find an alternative treatment for bovine mastitis without risking the environment.

The principle behind our proposal is the use of fused proteins based on efficient bacteriophage endolysins. The function of a bacteriophage is to infect bacteria in order to kill them. Once the bacteria are infected and the virions are mature, they release holins, which are enzymes that create pores in the inner cell membrane. Endolysins now have access to the cell wall, so they can degrade it. Endolysins have lytic activity for the purpose of setting free the phage progeny to continue infecting other cells [3]. Endolysins are composed of two main domains: the N-terminal, which represents the catalytic domain, and the C-terminal, which is a cell wall binding domain, which interacts by binding itself to the bacterium's cell wall, activating the catalytic region, and causing cell wall lysis. However, the average endolysin lifetime is 20 minutes [4] [3].

The main purpose of the PCNP is to counteract the endolysins' disadvantages to penetrate the Gram-negative cell membrane. The PCNP brings the opportunity to introduce our endolysins into the Gram-negative cell membrane through a principle related to the PCNP's ability to perform an ionic interaction between the phosphate groups, divalent cations, and hydrophobic lipids' stacking, resulting in the Gram-negative bacteria destabilization. Following this, the bacteria expose their peptidoglycan as a result of its destabilization, favoring its posterior lysis. Its part has been evaluated in Escherichia coli. The peptide has a length of nine amino acids [1].

References

[1] Briers, Y., Walmagh, M., Van Puyenbroeck, V., Cornelissen, A., Cenens, W., Aertsen, A., Oliveira, H., Azeredo, J., Verween, G., Pirnay, J.-P., Miller, S., Volckaert, G., & Lavigne, R. (2014). Engineered endolysin-based “Artilysins” to combat multidrug-resistant gram-negative pathogens. MBio, 5(4), e01379-01314. https://doi.org/10.1128/mBio.01379-14 ‌

[2] World Health Organization. (2021, November 17). Antimicrobial resistance. Who.int; World Health Organization: WHO. https://www.who.int/news-room/fact-sheets/detail/antimicrobial-resistance

[3] Gutiérrez, D., Fernández, L., Rodríguez, A., & García, P. (2018). Are phage lytic proteins the secret weapon to kill Staphylococcus aureus?. MBio, 9(1), 10-1128. https://doi.org/10.1128/mbio.01923-17

[4] Fernández, L., González, S., Campelo, A. B., Martínez, B., Rodríguez, A., & García, P. (2017). Downregulation of Autolysin-Encoding Genes by Phage-Derived Lytic Proteins Inhibits Biofilm Formation in Staphylococcus aureus. Antimicrobial Agents and Chemotherapy, 61(5), e02724-16. https://doi.org/10.1128/AAC.02724-16