Fig 4.
TprC is expressed at low abundance and is accessible to proteinase K in motile treponemes. (A) Quantitative immunoblot analysis of TprC expressed in T. pallidum. T. pallidum lysates in amounts indicated were immunoblotted with anti-TprCSp antiserum followed by densitometric analysis; a standard curve generated from densitometric values obtained for graded amounts of TprCFl was used to determine the copy number of TprC per T. pallidum cell. Molecular mass standards (kDa) are indicated on the left. (B) Immunoblot analysis of TprC, detected by the anti-TprCSp antiserum, in motile treponemes (1.0 × 108 T. pallidum organisms/lane) treated for 1 h with graded concentrations of proteinase K (PK). (C) PK accessibility of TprC and two periplasmic controls in intact and detergent-lysozyme-treated organisms incubated with (+) or without (−) 10 μg/ml of PK. Each lane represents 1.0 × 108 T. pallidum organisms immunoblotted with antisera to TprCSp, TP0453, or TroA. (D) Live imaging of intact treponemes with and without incubation with 100 μg/ml of PK. Asterisks and arrowheads indicate flexing and wave form propagation, respectively. Time scale is 0 to 0.12 s.