Bioinorganic Chemistry: CoFactors in Proteins

1
Bioinorganic Chemistry Co-Factors in
Proteins Costantinos Tsoukalis1, Dr. H.
Christopher Fry2, Dr. Michael Therein2

• Introduction
• Zinc Porphyrin co-factors (chromophores) have
  Non-linear Optic Properties
• 4 helix protein stabilizes Non-linear Optic
  Properties
• Possible uses in telecommunications

• Objectives
• Create Zinc porphyrin co-factor (Ru-PZn)
• Create a 4-helix protein bundle
• Imbed the co-factor in protein

• Materials
• Various organic solvents
• Silica gel columns
• Schlenk line apparatus (Air Free)
• Single point DNA mutation kits

• Methods
• Part 1 ? Synthesis of Co-Factor
• Followed RuPZn scheme
• Part 2 ? Expression of Protein
• Single Point DNA mutation
• Protein Expression from mutated DNA

• Results
• Part 1 ? Synthesis of Chromophore
• Co-factor synthesis was successful
• Purification of co-factor synthesis material was
  not possible
• Part 2 ?Protein Expression
• Single point mutations successful
• Codons for leucine and histidine present in DNA

• Conclusions
• Co-factor design went as planned
• RuPZn with extensive Non-Linear properties
  created
• Synthesis procedures must be followed precisely
  to ensure purification
• Protein design was successful
• Added time would have allowed for protein
  expression and imbedding of co-factor
• Titration of RuPZn and Protein was done with
  previously prepared samples

Literature Cochran, F.V., S.P. Wu, W. Wang, V.
Nanda, J.G. Saven, M.J. Therein and W.
DeGrado.2005. Computational De Novo Design and
Characterization of a Four-Helix Bundle Protein
that Selectively Binds a Nonbiological
Cofactor. Journal of American Chemical
Society. 1271346-1347. Lindsey, J.S., I.C.
Schreiman, H.C. Hsu, P.C. Kearney and A.M.
Marguerettaz. 1986. Rothemund and Alder-Longo
Reactions Revisited Synthesis of
Tetraphenylporphyrins under Equilibrium
Conditions. Journal of Organic Chemistry.
52827-836. Manka, J.S. and D.S. Lawrence. 1989.
High Yield Synthesis of 5,15
Diarylporphyrins. Tetrahedron Letters. vol. 30
no. 50, p. 6989- 6992. Uyeda, H.T., Y.
Zhao, K. Wostyn, I. Asselberghs, K. Clays, A.
Persoons and M.J. Therein. 2002. Unusual
Frequency Dispersion Effects of the
Nonlinear Optical Response in Highly Conjugated
(Polypyridyl)metal (Pophinato)zinc(II)
Chromophores. Journal of American
Chemistry. 12413806-13813.

• Acknowledgements
• Special thanks to Dr. H. Chris Fry for his
  guidance, along with all the members of the
  Therein group
• Thanks to the members of the DeGrado lab for
  help in expression of protein
• Thanks to the Drexel/University of Pennsylvania
  RET-Nano program for the opportunity

1. RET-Nano Participant, University of
Pennsylvania and Drexel University, Philadelphia,
PA. 2. University of Pennsylvania, Department of
Chemistry, Philadelphia, PA.