Fig. 3.

OmpLA arginine variants are stable and gradually acquire PK resistance in the absence of DegP. JMR352 transformed with pMDG2 or a pMDG2 derivative encoding the indicated OmpLA mutant were subjected to pulse-chase labeling after the addition of IPTG. The OM was permeabilized and half of each sample was treated with PK. Immunoprecipitations were then conducted using an anti-OmpLA antiserum. The percentage of the protein that remained and that was resistant to PK digestion at each time point is shown. Because it was not possible to distinguish proOmpLA from mature OmpLA in some of the pulse-labeled samples, the protein observed in untreated cells after a 2 min chase was defined as 100%.