Open AccessUse of a photoactivatable lipid to probe the topology of PA63 of Bacillus anthracis in lipid membranes
Author(s) -
Wang XiaoMing,
Wattiez Ruddy,
Brossier Fabien,
Mock Michèle,
Falmagne Paul,
Ruysschaert JeanMarie,
Cabiaux Véronique
Publication year - 1998
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1327.1998.2560179.x
Subject(s) - bacillus anthracis , anthrax toxin , transmembrane protein , peptide , proteolysis , membrane , biochemistry , chemistry , cytoplasm , membrane topology , residue (chemistry) , peptide sequence , liposome , transmembrane domain , biology , fusion protein , enzyme , receptor , recombinant dna , bacteria , gene , genetics
The protective antigen of Bacillus anthracis is a key protein that promotes the translocation of the enzymatic moieties of the two toxins of B. anthracis into the cell cytoplasm. The membrane topology of the active form of the protective antigen (PA63) was investigated by proteolysis of PA63 inserted into liposomes containing a photoactivatable, radioactive lipid, and characterization of the N‐terminal moiety of the deeply‐inserted (and therefore radiolabeled) peptides. A single sequence starting at residue Ala258 was identified. Fourier‐transform infrared spectroscopy showed that the protected peptide was mainly adopting a β‐sheet structure whose orientation was compatible with a transmembrane organization.