PhD Scientific Days 2024

Budapest, 9-10 July 2024

Poster Session E - Molecular Medicine 2.

Glucan binding protein C specific DNA Aptamer shows inhibitory potential


Ákos Harkai1, Yoon Kee Beck1, Anna Tory1, Brigitta Kállai1, Tamás Mészáros1
1: Institute of Biochemistry and Molecular Biology

Text of the abstract

Biofilm as a microbial virulence factor is a widespread survival tool for most prokaryotic species. In many cases, biofilm-forming bacteria are protected from the prevailing conditions and can thus become resistant to various disinfection procedures and antimicrobial treatments.
The use of a panel of antibiotics is still the gold standard in healthcare, but certain pathogenic bacteria are able to rapidly adapt to these drugs and develop new survival strategies against them. As a result, there is a need to develop effective biological molecules that can provide specific and long-lasting protection against harmful strains. Although the inhibition of bacterial growth by blocking biofilm formation is a relatively new frontier, the available circular peptides, monoclonal antibodies and aptamers appear to be a promising approach for defence against bacterial pathogens.
The focus of our research is the selection and application of aptamers specific for the cell surface protein GbpC of Streptococcus mutans UA130. GbpC plays a cardinal role in the formation of streptococcal biofilms, thereby promoting the development of dental caries. Specific inhibition of GbpC target with an aptamer can help to eliminate this important virulence factor, thereby mitigating and preventing oral diseases.
Based on our results, we succeeded in selecting GbpC-specific DNA aptamers, which was confirmed by demonstrating the GbpC-aptamer interaction by various methods. The applicability of the selected aptamers was tested in biofilm inhibition assays using wild-type and ΔGbpC S. mutans strains. With two candidate aptamers, we observed a significant biofilm reducing effect in the case of the wild-type but not in the ΔGbpC strain. We also investigated the diagnostic ability of the selected aptamers with our flow cytometric measurements.
Our future goal is to develop the efficacy of these aptamers by elucidating the atomic-level spatial structure of the aptamer-GbpC complex using X-ray crystallography.