The Observation of Insoluble Proteins in Solution

1
The Observation of Insoluble Proteins in Solution

• Group 23 Members
• Scott Dobson
• Jeff Schomer
• Mike Connor
• Scott Crick (Mentor)

2
The Need

• Protein (amyloid beta) involved in
  nerodegenerative diseases.
• Want to find polymeric properties of this protein
  through microscopy.
• Properties could lead to method for breaking up
  the proteins.
• The problem is that these proteins sink to the
  bottom of the observation glass.

3
Scope

• Design a device to keep negatively charged
  protein molecules suspended in solution
  consisting of
• Tunable electric field
• Power source
• Preferably able to interface with observation
  glasses in the lab.

4
Design Requirements

• Trap protein in a 10 µm range.
• Tunable electric field.
• Power source small enough to fit on 3ft by 2ft
  laboratory cart top.
• Budget flexible, around 3,000.
• Preferably able to interface with observation
  glasses in the lab.

5
Existing Solutions

• ABEL (anti-Brownian electrophoretic) trap
• Traps molecules in two dimensions.
• Uses feedback loop to re-center molecule.
• Complicated
• Cohen, et al.

6
Existing Solutions

• Optical Laser Tweezers
• Use laser beam to trap molecule.
• Works on micrometer scale objects, not nanometer.
• Ashkin, et al.

7
Existing Solutions

• Trapping of DNA molecules in nonuniform
  oscillating electric field.
• Narrow strips of gold film placed 30 micrometers
  apart.
• Voltage applied from platinum wires on the side.
• Asbury, et al.

8
Preliminary Calculations

• Parameters
• Assume 5,000 monomers per protein molecule
• Length of protein chain 10 micrometers
• Length of monomer 4 angstroms
• 2 fibrils per protein chain
• Viscosity of water 8.9410-4 Pa s
• Assume radius of 40 nanometers (Carrotta, et al)
• Charge per monomer -2.4e
• Molecular Weight 4,500 g/mol
• Calculated Density 1,550 Kg/m3
• Settling Velocity of Protein in Water 2.143
  x10-3 m/s
• Vs (2/9)gr2/(µ)(pm-pw)
• Time to travel 10 micrometers .00467s

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Preliminary Calculations

• Time to travel 10 micrometers due to Brownian
  motion 8.14s
• t d2/(2DAB)
• DAB KT/(6pirµ) 610-12

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Schedule

• 10/3 Written Preliminary Report
• 10/12 Determine All Design Alternatives
• 10/16 Pick a Design
• 10/20 Determine Details for our Design
• 10/21 Update Design Schedule/Team
  Responsibilities
• 10/22 Progress Oral Report
• 10/29 Progress Written Report
• 11/28 Design Safe Software
• 12/5 Final Oral Report
• 12/5 Final Written Report Due
• 12/12 Senior Project Poster

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Organization of Responsibilities

• Scott
• Preliminary Oral Report
• Communication with mentor, teachers, and outside
  sources
• Setting up meetings
• Weekly reports
• Jeff
• Progress Oral Report
• Electrical
• Sketches, Diagrams, and Figures
• Mike
• Final Oral Report
• Literature Searches
• Mechanical
• Web page
• Joint work
• Design Safe
• Written Reports

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References

• Asbury, C.L., Engh, G. Trapping of DNA in
  Nonuniform Oscillating Electric Fields.
  Biophysics Journal, 74, 1024-1030.
• A. Ashkin, J.M. Dziedzic, J.E. Bjorkholm, and S.
  Chu, (1986) Optical Letters, 11, 288.
• Carrotta, R., Barthes, J., Longo, A., Mortarana,
  A., Manno, M., Portale, A., Biagio, P. (2007).
  Large size fibrillar bundles of the Alzheimer
  amyloid beta-protein. European Biophysics, 36,
  701-709.
• Cohen, A., Moerner, W.E. (2005). Method for
  trapping and manipulating nanoscale objects in
  solution. Applied Physics Letters, 86.

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Questions