Bactericidal properties of Proline-Rich Aedes aegypti Trypsin Modulating Oostatic Factor (AeaTMOF)

Authors: BOROVSKY, DOV - University Of Colorado; ROUGÉ, PIERRE - Faculty Of Pharmaceutical Sciences; Shatters, Robert - Bob

Submitted to: Life
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/19/2022
Publication Date: 12/21/2022
Citation: Borovsky, D., Rougé, P., Shatters, R.G. 2022. Bactericidal properties of Proline-Rich Aedes aegypti Trypsin Modulating Oostatic Factor (AeaTMOF). Life. 13(1), 19. https://doi.org/10.3390/life13010019.
DOI: https://doi.org/10.3390/life13010019

Interpretive Summary: Antimicrobial peptides represent a tremendously diverse class of biological molecules that could be used in agriculture for the protection of plants and animals against bacterial infections. Proline rich AMPs represent a sub-class of these peptides. A proline rich peptide from mosquitoes that has previously been shown to be an insect peptide hormone that, when introduced orally to mosquito larvae and other insects, induced insect mortality. This peptide was shown to be involved in controlling the digestion of a blood meal by adult female mosquitoes. However, in this report we show that the peptide has bi-functional activity: control of blood meal digestion and antimicrobial activity. Our work demonstrated the breadth of activity of TMOF against various bacterial types and demonstrated how the TMOF enters the bacterial cells. These results show that the TMOF may be a suitable candidate for controlling a number of economically and human health related bacteria.

Technical Abstract: The antimicrobial properties of proline-rich Aedes aegypti decapeptide TMOF (AeaTMOF) and oncocin112 (1–13) were compared. Incubations with multidrug-resistant Escherichia coli cells showed that AeaTMOF (5 mM) was able to completely inhibit bacterial cell growth, whereas oncocin112 (1–13) (20 mM) partially inhibited bacterial growth as compared with bacterial cells that were not multidrug-resistant cells. AeaTMOF (5 mM) was very effective against Acinetobacter baumannii and Pseudomonas aeruginosa, completely inhibiting cell growth during 15 h incubations. AeaTMOF (5 mM) completely inhibited the Gram-positive bacteria Staphylococcus aureus and Bacillus thurengiensis sups. Israelensis cell growth, whereas oncocin112 (1–13) (10 and 20 mM) failed to affect bacterial cell growth. E. coli cells that lack the SbmA transporter were inhibited by AeaTMOF (5 mM) and not by oncocin112 (1–13) (10 to 20 mM), indicating that AeaTMOF can use other bacterial transporters than SbmA that is mainly used by proline-rich antimicrobial peptides. Incubation of E. coli cells with NaAzide showed that AeaTMOF does not use ABC-like transporters that use ATP hydrolysis to import molecules into bacterial cells. Three-dimensional modeling and docking of AeaTMOF to SbmA and MdtM transporters showed that AeaTMOF can bind these proteins, and the binding location of AeaTMOF inside these protein transporters allows AeaTMOF to be transported into the bacterial cytosol. These results show that AeaTMOF can be used as a future antibacterial agent against both multidrug-resistant Gram-positive and -negative bacteria.