J. Biol. Chem., Vol. 264, Issue 23, 13559-13564, Aug, 1989
Identification of a hemolysin from Actinobacillus pleuropneumoniae and characterization of its channel properties in planar phospholipid bilayers
G Lalonde, TV McDonald, P Gardner and PD O'Hanley
Department of Microbiology, Stanford University School of Medicine, California 94035.
A proteinaceous hemolysin secreted by strain 4074 of serotype 1 of
Actinobacillus pleuropneumoniae was purified by diafiltration and ion
exchange chromatographic techniques. The hemolytic activity is associated
with a 107-kDa band as assessed by sodium dodecyl sulfate- polyacrylamide
gel electrophoresis analysis and confirmed by Western blotting and
immunoprecipitation. This hemolysin produces pores in membranes as
demonstrated by osmotic protection studies using red blood cells and
carbohydrate compounds of various molecular weights. These assays suggest a
pore diameter in the order of 2 nm. Phospholipid bilayers composed of 1:1
w/w phosphotidylserine:phosphotidylethanolamine exposed to this toxin
display discrete current flow events typical of transmembrane channels and
consistent with the interpretation that this toxin acts by forming pores in
phospholipid membranes. The linear relationship of current amplitude to
holding potential when examined over the -60 to +60 mV range indicates that
this pore has a constant mean single channel conductance level of 350-400
pS.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
