Structure of a premicellar complex of alkyl sulfates with the interfacial binding surfaces of four subunits of phospholipase A2

  • Pan Y
  • Bahnson B
  • 3

    Readers

    Mendeley users who have this article in their library.
  • 4

    Citations

    Citations of this article.

Abstract

The properties of three discrete premicellar complexes (E1#, E2#, E3#) of pig pancreatic group-IB secreted phospholipase A2 (sPLA2) with monodisperse alkyl sulfates have been characterized [Berg, O. G. et al., Biochemistry 43, 7999-8013, 2004]. Here we have solved the 2.7 Å crystal structure of group-IB sPLA2complexed with 12 molecules of octyl sulfate (C8S) in a form consistent with a tetrameric oligomeric that exists during the E1#phase of premicellar complexes. The alkyl tails of the C8S molecules are centered in the middle of the tetrameric cluster of sPLA2subunits. Three of the four sPLA2subunits also contain a C8S molecule in the active site pocket. The sulfate oxygen of a C8S ligand is complexed to the active site calcium in three of the four protein active sites. The interactions of the alkyl sulfate head group with Arg-6 and Lys-10, as well as the backbone amide of Met-20, are analogous to those observed in the previously solved sPLA2crystal structures with bound phosphate and sulfate anions. The cluster of three anions found in the present structure is postulated to be the site for nucleating the binding of anionic amphiphiles to the interfacial surface of the protein, and therefore this binding interaction has implications for interfacial activation of the enzyme. © 2010 Elsevier B.V. All rights reserved.

Author-supplied keywords

  • Interfacial enzyme
  • Membrane associated protein
  • Premicellar complex
  • sPLA2, alkyl sulfate

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Authors

  • Ying H. Pan

  • Brian J. Bahnson

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free