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Alan Finkelstein, Ph.D. Professor |
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Alan Finkelstein, Ph.D. Professor |
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Ion-Conducting Channels Incorporated into Planar Lipid Bilayer Membranes Faculty Record For the past several years we have been
studying the voltage-dependent channels formed in planar phospholipid
bilayer membranes by diphtheria toxin, colicin Ia and anthrax toxin. The
remarkable finding we have discovered with the former two channels is that
in association with their opening and closing there is a massive
translocation of material back and forth across the membrane. In the case of
diphtheria toxin, this consists of the N-terminal 270 residues, and in the
case of colicin Ia, a region of at least 70 residues. Moreover, we have
shown with the colicin that foreign epitopes inserted in this region are
also translocated. Thus these molecules appear to be capable of
translocating "any" sequence of polar residues. Our research is directed at
deducing the channel structure, identifying the voltage sensor, and
determining the mechanism and pathway of protein translocation. |