Fig. 5.

Effects of PNt contraction on pertactin secretion in vivo. (A) Secretion of wild-type pertactin and swap variant chimeras, monitored by the intramolecular cleavage of the pertactin precursor (93 kDa apparent MW) to the smaller mature passenger (69 kDa apparent MW) in whole-cell lysate samples, detected using an anti-pertactin passenger antibody. Gel mobility differences for some swap variants are attributed to the altered distributions of charged residues. (B–D) Quantification of (B) precursor, (C) passenger, and (D) total pertactin accumulated (precursor + passenger) as a function of ν. Vertical error bars represent SEM for three replicates; bars not visible are smaller than the data point. Horizontal error bars are the error in the MFF fit (Fig. 2 and refs. 3 and 5). Swap2, which formed soluble oligomers under all conditions tested, is displayed with an estimated ν of 0.33 and was excluded from the statistical analysis. The wild-type protein was also excluded from the correlation analysis due to the separate influence of its folding on secretion efficiency (see fourth paragraph of text section titled Expanded PNt Conformations Facilitate Efficient Pertactin Secretion to the Bacterial Cell Surface). The P values were calculated by parametric bootstrap (Materials and Methods).