European Biophysics Journal

, Volume 32, Issue 7, pp 589–598 | Cite as

A statistical investigation of amphiphilic properties of C-terminally anchored peptidases

  • James Wallace
  • Frederick Harris
  • David A. Phoenix


A number of DD-peptidases have been reported to interact with the membrane via C-terminal amphiphilic α-helices, but experimental support for this rests with a few well-characterized cases. These show the C-terminal interactions of DD-carboxypeptidases to involve high levels of membrane penetration, DD-endopeptidases to involve membrane surface binding and class C penicillin-binding proteins to involve membrane binding with intermediate properties. Here, we have characterized C-terminal α-helices from each of these peptidase groups according to their amphiphilicity, as measured by mean <μH>, and the corresponding mean hydrophobicity, <H>. Regression and statistical analyses showed these properties to exhibit parallel negative linear relationships, which resulted from the spatial ordering of α-helix amino acid residues. Taken with the results of compositional and graphical analyses, our results suggest that the use of C-terminal α-helices may be a universal feature of the membrane anchoring for each of these groups of DD-peptidases. Moreover, to accommodate differences between these mechanisms, each group of C-terminal α-helices optimizes its structural amphiphilicity and hydrophobicity to fulfil its individual membrane-anchoring function. Our results also show that each anchor type analysed requires a similar overall balance between amphiphilicity for membrane interaction, which we propose is necessary to stabilize their initial membrane associations. In addition, we present a methodology for the prediction of C-terminal α-helical anchors from the classes of DD-peptidases analysed, based on a parallel linear model.


C-terminal amphiphilic α-helix DD-peptidase Membrane anchoring Penicillin-binding protein Regression with categorical predictors 


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Copyright information

© EBSA 2003

Authors and Affiliations

  • James Wallace
    • 2
  • Frederick Harris
    • 3
  • David A. Phoenix
    • 1
  1. 1.Dean's Office, Faculty of ScienceUniversity of Central LancashirePrestonUK
  2. 2.Department of Physics, Astronomy and MathematicsUniversity of Central LancashirePrestonUK
  3. 3.Department of Forensic and Investigative ScienceUniversity of Central LancashirePrestonUK

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