000133466 001__ 133466
000133466 005__ 20181203021431.0
000133466 0247_ $$2doi$$a10.1021/bi00061a023
000133466 037__ $$aARTICLE
000133466 245__ $$aOligomerization of the channel-forming toxin aerolysin precedes insertion into lipid bilayers
000133466 269__ $$a1993
000133466 260__ $$c1993
000133466 336__ $$aJournal Articles
000133466 500__ $$aDepartment of Biochemistry and Microbiology, University of Victoria, British Columbia, Canada.
000133466 520__ $$aOligomerization is a necessary step in channel formation by the bacterial toxin aerolysin. We have identified a region of aerolysin containing two tryptophans which influence the ability of the protein to oligomerize. Changing the tryptophan at position 371 or 373 to leucine resulted in mutant proteins that oligomerized at much lower concentrations than the wild-type toxin. Near-ultraviolet circular dichroism measurements showed that the tertiary structures of the L-371 and L-373 mutant toxins may be slightly different from the structure of wild type. Other single amino acid replacements in the same region of the protein as the two tryptophans appeared to have little or no effect on any properties of the protein. None of the changes we made had any measured effect on secretion of the protein by the bacteria. The L-373 and L-371 proteins induced chloride release from liposomes at lower concentrations than native toxin. Wild-type aerolysin solutions were completely unable to cause release when oligomeric toxin was absent or when it was removed by centrifugation. Aerolysin changed at H-132, which cannot form oligomers, was also inactive against liposomes. We conclude that aerolysin channels are produced by direct insertion of oligomers formed in solution, or assembled on the surface of the cell after binding to the receptor, and not by lateral diffusion of the monomer after it enters the lipid bilayer.
000133466 6531_ $$aAmino Acid Sequence
000133466 6531_ $$aBacterial Toxins/*chemistry/genetics/pharmacology
000133466 6531_ $$aBase Sequence
000133466 6531_ $$aChlorides
000133466 6531_ $$aCodon/genetics
000133466 6531_ $$aEscherichia coli/genetics
000133466 6531_ $$aFluorescent Dyes
000133466 6531_ $$aHemolysin Proteins/*chemistry
000133466 6531_ $$aHemolysis
000133466 6531_ $$aHumans
000133466 6531_ $$a*Ion Channels
000133466 6531_ $$aKinetics
000133466 6531_ $$a*Lipid Bilayers
000133466 6531_ $$aMacromolecular Substances
000133466 6531_ $$aMutagenesis
000133466 6531_ $$aSite-Directed
000133466 6531_ $$aPore Forming Cytotoxic Proteins
000133466 6531_ $$a*Protein Structure
000133466 6531_ $$aTertiary
000133466 6531_ $$aRecombinant Proteins/chemistry/pharmacology
000133466 6531_ $$a*Tryptophan
000133466 700__ $$0240085$$g171549$$avan der Goot, F. G.
000133466 700__ $$aPattus, F.
000133466 700__ $$aWong, K. R.
000133466 700__ $$aBuckley, J. T.
000133466 773__ $$j32$$tBiochemistry$$k10$$q2636-42
000133466 909C0 $$xU11271$$0252037$$pVDG
000133466 909CO $$pSV$$particle$$ooai:infoscience.tind.io:133466
000133466 937__ $$aVDG-ARTICLE-1993-001
000133466 973__ $$rREVIEWED$$sPUBLISHED$$aOTHER
000133466 980__ $$aARTICLE