(Georgia Institute of Technology, 2015-06-30)
Yohannan, Jiby
Understanding the chemistry of metalloproteins can lead to innovative solutions to major problems in fields such as energy conservation and drug development. In nature, there are numerous biological proteins that use metal cofactors as part of their function. For example, Photosystem II contains a manganese-core that assists with the oxygen evolution process. Without the metal cluster, the protein is unable to produce the final products of photosynthesis. Carbonic anhydrase is another biological protein that needs zinc to convert carbon dioxide into bicarbonate. The zinc plays a critical role in the interchangeable conversion of these two molecules. By understanding the interactions between the metal and the protein, it is possible to harness the chemistry of these biological systems for commercial purposes.
This study investigates the interactions between a biologically inspired designed peptide and metals. Biomimetic peptide models, also referred to as maquettes, can be designed and used to study specific portions of complex biological proteins. This study has designed a peptide that contains the appropriate amino acid residues to facilitate metal binding. By introducing various relevant metals to the peptide system, spectroscopic methods were used to determine if the metal is binding. The results showed that the metal did indeed bind to the synthesized peptide. This study will provide a better understanding of the influence of metals in biological systems, and how these characteristics may be applied for synthetic purposes.
(Georgia Institute of Technology, 2014-04-25)
McDaniel, Miranda Jade
Proton coupled electron transfer (PCET) is a mechanism exploited by many biological processes including the oxygen evolving complex (OEC) of photosystem II. PCET functions largely by the formation of a stable radical species. One amino acid with the ability to form such a stable cation radical is tryptophan. In this study, biomimetic beta-hairpin peptides have been synthesized with a cross-strand interacting tryptohan residue. The peptides have been characterized by circular dichroism spectroscopy, to be further explored by electrochemistry and electron paramagnetic resonance (EPR) spectroscopy. These techniques will provide insight into the formation of the tryptophan radical, the factors influencing its stabilization, the effect of the local amino acid environment, and, ultimately, the fundamentals of proton coupled electron transfer.