Biophysical Society Thematic Meeting | Stockholm 2022

Physical and Quantitative Approaches to Overcome Antibiotic Resistance

Tuesday Speaker Abstracts

THE ROLE OF PROTEIN MECHANOSTABILITY IN ANTIBIOTIC RESISTANCE Priscila SFC Gomes 1 ; Diego Enry B Gomes 1 ; Lukas F Milles 2,3 ; Hermann E Gaub 3 ; Rafael C Bernardi 1 ; 1 Auburn University, Department of Physics, Auburn, AL, USA 2 University of Washington, Institute for Protein Design, Seattle, WA, USA 3 Ludwig-Maximilians-University, Lehrstuhl für Angewandte Physik and Center for Nanoscience, Munich, Germany Gram-positive pathogenic bacteria have an arsenal of virulence factors to target and adhere to their host. Among these virulence factors, adhesins play critical roles during infection participating actively on the formation of biofilm. The extreme mechanostability of the interaction between pathogenic adhesins and proteins of the human extracellular matrix have been shown to pose a major challenge to traditional drug-development routes. Here, we show that adhesins from methicillin resistant Staphylococcus aureus (S. aureus) strains (MRSA) are more resilient to shear forces than those of methicillin susceptible strains (MSSA). Combining a myriad of state-of-the-art computational biology approaches we show that, although methicillin does not act on the adhesins, the MRSA strains have mutations on these proteins that give them extreme mechanostability. In fact, the complex formed between adhesins and proteins of the human extracellular matrix are the strongest protein interactions known, surpassing by an order of magnitude the strength of streptavidin-biotin. To discover that, we employed bioinformatic tools to retrieve and align nearly 200 proteins of the bacterial adhesin superfamily. Using AI based protein structure prediction, we modelled adhesins of interest from MSSA and MRSA strains, together with their human target. Using NAMD, steered molecular dynamics (SMD) simulations were performed using a wide-sampling paradigm. This protocol allowed us to investigate how adhesins can sense forces and become activated to resist high shear hydrodynamic force loads found during host infection. For representative strains, experimental validation was given by single molecule force spectroscopy experiments. In summary, the extreme mechanostability of all strains with a pattern of higher forces for the MRSA strains was observed. With increasing prevalence of multidrug resistant bacterial infections, this new finding could be exploited for the development of antiadhesion strategies as an innovative alternative to antibiotics.

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