G. Andrew Woolley

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The photoisomerization of azobenzene has been known for almost 75 years but only recently has this process been widely applied to biological systems. The central challenge of how to productively couple the isomerization process to a large functional change in a biomolecule has been met in a number of instances and it appears that effective photocontrol of a(More)
We have discussed in some detail a variety of experimental studies which were designed to elucidate the conformational and dynamic properties of gramicidin and alamethicin. Although the behavior of these peptides is by no means fully characterized, these studies have already permitted aspects of ion channel activity to be understood in molecular terms.(More)
We report here an approach for simultaneous fluorescence imaging and electrical recording of single ion channels in planar bilayer membranes. As a test case, fluorescently labeled (Cy3 and Cy5) gramicidin derivatives were imaged at the single-molecule level using far-field illumination and cooled CCD camera detection. Gramicidin monomers were observed to(More)
Photocontrolled transcription factors could be powerful tools for probing the role of transcriptional processes in settings that are spatially or temporally complex. We report the structure-based design of a photocontrolled bZIP-type DNA binding protein that is a hybrid of the prototypical homodimeric bZIP protein GCN4 and photoactive yellow protein (PYP),(More)
A mutant of Photinus pyralis luciferase in which all four native cysteine residues are converted to serines retains about 10% of wild-type activity. This mutant should prove useful as a starting point for the introduction of biophysical probes of conformational changes associated with enzyme function. The activities of the cysteine-free mutant and others in(More)
Photo-triggered alpha-helix formation of a 16-residue peptide featuring a built-in conformational photoswitch is monitored by time-resolved IR spectroscopy. An experimental approach with 2-ps time resolution and a scanning range up to 30 micros is used to cover all time scales of the peptide dynamics. Experiments are carried out at different temperatures(More)
BACKGROUND Antiamoebin is a member of the peptaibol family of polypeptides and has a unique antibiotic activity: it acts as an antiamoebic agent, but does not effectively haemolyze erythrocytes even though it does exhibit membrane-modifying activity. RESULTS The structure of antiamoebin I has been determined by X-ray crystallography at 1.4 A resolution.(More)
The interaction of the voltage-dependent channel-forming peptide alamethicin with dioleoylphosphatidylcholine (DOPC) small unilamellar vesicles (SUV) has been studied using circular dichroism spectroscopy over a range of wavelengths and temperatures. Evidence is presented for the existence of two distinct membrane-bound states of the peptide which reflect(More)
The attempt frequency or prefactor (k0) of the transition-state rate equation of protein folding kinetics has been estimated to be on the order of 10(6) s(-1), which is many orders of magnitude smaller than that of chemical reactions. Herein we use the mini-protein Trp-cage to show that it is possible to significantly increase the value of k0 for a protein(More)
A sensitive assay for ribonuclease A activity based on the relief of fluorescence quenching within a defined oligomeric substrate (5' fluorescein-AAAArUAAAA-3'-rhodamine) is described. The substrate can be produced using an automated nucleic acid synthesizer and commercially available reagents. Together with a nonfluorescent cosubstrate(More)