Recordings of C-terminus-first translocation events of Trx-linker nonamers (left), showing a distinct level A1 (boxed in purple, green or yellow) in the presence of a PTM compared with the level A1 of unmodified units (orange dash). Traces have been filtered at 2 kHz; transient A3 levels were truncated by filtering and therefore deviate from ~0 pA. The A3 level produced by the translocation of an unmodified unit before the modified linker is indicated with a blue arrow and each of the features A is indicated by orange and blue bars. The number of repeats of feature A within the polypeptide translocation event shown is specified. Scatter plots of I r.m.s. and I res% for individual polypeptide translocation events (right), where I res% = < I res% (A1, Trx-linker)> – I res% (A1, Trx-linker + PTM), where < I res% (A1, Trx-linker)> is the mean I res% value of the remaining A1 levels for unmodified repeat units within an individual translocation event. Conditions, 375 mM GdnHCl, 375 mM KCl, 10 mM HEPES at pH 7.2, 1.2 M Trx-linker nonamer ( cis ), +140 mV ( trans ), 24 1 C.
