Anionic polymers of Bacillus subtilis cell wall modulate the folding rate of secreted proteins

In order to characterize the dynamics of the interaction between the emerge nt membrane translocated exoprotein and the components of Bacillus subtilis cell wall, we examined the kinetics of the in vitro refolding of levansucr ase and alpha-amylase, at pH 7 and 37 degrees C, in the presence of polypho sphates (polyP) of various chain lengths (2 less than or equal to n less th an or equal to 65). These soluble anionic polymers are considered here to m imic the role of teichoic acids. Even in the absence of calcium, levansucra se rapidly refolded in the presence of polyP of n greater than or equal to 16. In contrast, polyP modulate indirectly the rate of a-amylase refolding via their affinity for calcium. These differential effects might explain th at the rate of the cell wall translocation of oc-amylase secretion was foun d to be half that of levansucrase. (C) 1999 Federation of European Microbio logical Societies. Published by Elsevier Science B.V. All rights reserved.