Kinetic Analysis of Bacteriophage Sf6 Binding to Outer Membrane Protein A Using Whole Virions

Natalia B. Hubbs; Mareena M. Whisby-Pitts; Jonathan L. McMurry

The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. . https://doi.org/10.1101/509141 doi: bioRxiv preprint the work presented here was completed solely with purified OmpA. Our previous work showed that keeping LPS constant, but varying different OmpAs resulted in differences of ejection efficiencies and rates in vitro [23] . Since both components are required for infection [23, 25] , it may be possible that the LPS helps to "prime" the phage to interact with OmpA, by inducing a subtle, initial conformational change that could induce different interactions with OmpA loop variants. Future work includes building on our current platform and will include a much more complex binding landscape. Ultimately, we hope to expand these studies to liposomes containing LPS and OmpA and/or whole S. flexneri cells to better elucidate the mechanistic properties of the Sf6 infection process. The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. . https://doi.org/10.1101/509141 doi: bioRxiv preprint then-dissociation non-linear fits are shown as solid black lines. Association and dissociation times were 300 s. Residuals are shown below the sensorgrams and are less than 10% of the total signal. Kinetic and equilibrium dissociation constants determined from the sensorgrams are shown in Table 1 . Kinetic and equilibrium dissociation constants generated from the sensorgrams are shown in Table 2 . where it then interacts with OmpA. The crystal structure of E.coli OmpA (PDB: 1BXW) is depicted as a ribbon diagram using UCSF Chimera [52] . Interaction with OmpA likely triggers a conformational change in the tail machinery.