Biofilms are a routine issue in bioprocessing and healthcare, causing antibiotic resistance where they form. The curli protein binds E. coli together in order for them to form biofilms, and CsgA is the primary structural component of this protein. As the primary function of CsgA is focused on maintaining the structure of the curli protein, analysing its structural mechanics is essential in developing strategies to overcome its formation in future research. Optical tweezer experiments carried out at Dr. Derek Dee’s lab in the Department of Land and Food Sciences (LFS) at the University of British Columbia (UBC) have been conducted to pull at both ends of the protein to determine the force-extension curve of CsgA in order to determine the internal strength of the protein. Steered molecular dynamics simulations can shed light on the details of the process of unfolding in these scenarios at an atomic level. Several common unfolding patterns are identified, like the rapid unfolding of R4/R5 and R3/R4 and the formation of anti-parallel β-sheets in N22/R1 during the simulations. The simulations show their usefulness in future research dedicated to combatting biofilm formation by highlighting the strength and unfolding tendencies of the structures that maintain these biofilms, and open the door to research that can develop chemicals that can disrupt these structures.
Kirill Kudriavtsev (Thu,) studied this question.