Fig 1

Fig 1

Selection of MEndoB from a library of chimeric staphylococcal PGHs. A chimeric PGH library of 48 constructs was cloned, expressed, and characterized (A). Constructs were screened for activity in PBS and human serum with two orthogonal assays (turbidity reduction assay and quantitative killing assay [qKA]) against S. aureus and S. epidermidis. The most active construct (MEndoB) was further tested in vitro, ex vivo, and in vivo. MEndoB comprises two EADs (N-terminal CHAP domain [blue] and the central M23 endopeptidase domain [yellow]), one CBD (C-terminal SH3b domain [green]), and two linkers (purple and pink) from different origins, shown in a 3D-modeled ribbon representation (ColabFold). Activity of MEndoB against S. aureus ATCC 12600 (B) and S. epidermidis ATCC 35984 (C) in human serum, as determined by qKAs. Activity of C-terminally His-tagged versions of MEndoB, SAL-1, and PlySs2 in human serum against S. aureus ATCC 12600 (D) and S. epidermidis ATCC 12228 (E), determined by qKAs. The limit of detection was 200 CFUs/mL (dotted line), and error bars represent standard error of the mean from four (B and C) and two (D and E) biological replicates. Figure was modified from reference 32 and created using biorender.com.