Use of a photoactivatable lipid to probe the topology of PA63 of Bacillus anthracis in lipid membranes.
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 beta-sheet structure whose orientation was compatible with a transmembrane organization.
Wang
X M
XM
Laboratoire de Chimie Physique des Macromolécules aux Interfaces, CP 206/2, Université Libre de Bruxelles, Brussels, Belgium.
Wattiez
R
R
Brossier
F
F
Mock
M
M
Falmagne
P
P
Ruysschaert
J M
JM
Cabiaux
V
V
D000942:Antigens, Bacterial; D001408:Bacillus anthracis / Q000276:immunology*; D001427:Bacterial Toxins / Q000737:chemistry*; D006868:Hydrolysis; D008027:Light; D008055:Lipids; D008565:Membrane Proteins / Q000737:chemistry; D015335:Molecular Probes; D010777:Photochemistry; D017433:Protein Structure, Secondary; D011510:Proteolipids; D017550:Spectroscopy, Fourier Transform Infrared
D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D008055:Lipids; D008565:Membrane Proteins; D015335:Molecular Probes; D011510:Proteolipids; C030325:anthrax toxin; C020485:proteoliposomes