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SUMMARY:Electrochemically-assisted protein crystallisation: Applications t
 o biosensors - Professor Abel Moreno
DTSTART:20090401T091500Z
DTEND:20090401T100000Z
UID:TALK16533@talks.cam.ac.uk
CONTACT:7011
DESCRIPTION:Protein/enzyme immobilization on electrode surfaces has been l
 imited to soluble biomolecules. However\, recent developments in protein c
 rystallisation have created an interest in the study of solid-state electr
 ochemistry of protein single crystals in order to understand the mechanism
 s of crystal growth coupling these biological crystals to fluid cells for 
 atomic force microscopy (AFM) investigations. Unfortunately\, the fixation
  of these monocrystals to an electrode surface is difficult since the mono
 crystals break easily under mechanical pressure\, and therefore they canno
 t be immobilised in the same way as inorganic crystals. From this point of
  view\, it is feasible to grow ex situ redox metalloprotein single crystal
 s (such as catalases\, ferritins\, cytochromes\, etc) so that they can be 
 introduced into the fluid cell of the atomic force microscope (AFM) to inv
 estigate electron-transfer processes\, mechanisms of crystal growth or get
  technological applications of the biological crystals as biosensors.  In 
 order to immobilize these biological crystals or particles\, it is shown h
 ow the use polypyrrole (ppy) films deposited on highly oriented pyrolytic 
 graphite electrodes (HOPG) or Indium Tin Oxide electrodes (ITO) allow us t
 o perform structural investigations via EC-AFM techniques. \n\n\nIn summar
 y\, the basic strategies to control the kinetics and transport phenomena o
 f the crystal growth process are reviewed\, as well as novel methods to in
 duce either nucleation or protein crystal growth via electrochemical proce
 sses (protein electrochemically-assisted protein crystallisation). Additio
 nally\, recent advances\, where low direct/alternant current or voltages a
 re applied to the crystal growth cell to obtain high-quality single crysta
 ls for X-ray diffraction\, are also discussed. This also permitted to deve
 lop a first prototype of a solid-state electron-transfer device based on b
 iological crystals. Finally\, using the electrochemistry modulus of the AF
 M\, cyclic voltammetry techniques were performed in order to characterize 
 the electron-transfer response on the surface of these crystals attached t
 o the electrode. The potential applications of these methods for the devel
 opment of protein-based biosensors are discussed in this seminar.
LOCATION:Seminar Room\, Sanger Building
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