NSF-funded research in the Cammers group focuses on the study of the minimalist global conformation in a biomimetic family of chiral oligoureas. We are using this system to understand the basis of structure in large molecules that are too small to benefit from the high cooperativity of natural proteins. Results thus far demonstrate that the oligourea chains are structured with respect to CD and that these CD curves readily melt at chain lengths much shorter than corresponding studies with peptides. We plan analogous NMR studies of conformational bias as a function of solvent and temperature.
This project is ready for undergraduate involvement. The high risk, slow synthetic investigations are done. We know how to make the material. We know the conditions under which the chains are soluble and we know which combinations of hetero and homochiral residues promote solubility. The summer experience for the student must be highly focused and goal oriented to get anything at all out of the time spent in an unknown environment. The undergraduate REU student will synthesize oligomers from commercially available units to
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Pentameric oligourea crystallized in extended conformation
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investigate possible structure breakage as assessed by CD. We need to know how a random chain behaves to compare it with obviously structured units. Interrupting chiral continuity by achiral, unrestricted units will give us a better idea of how the chiral residues are communicating to give rise to the strongly temperature- dependent CD curves. The results will be immediate and publishable in the context of a larger study. The planned studies provide the student with an intense opportunity to pick up new skills related to molecular design, computational chemistry, and working and thinking at an interface between Biochemistry and Chemistry.
In related work Cammers and coworkers design and synthesize peptides capable of binding two copper atoms proximal to one another to investigate the chemistry of related species capable of transporting molecular oxygen in bacterial systems. This is an ongoing collaboration with Professor David Rockcliffe at Kentucky State University. Students from Kentucky State who earn a summer position in this NSF-REU program would make use of Cammers' computational and peptide synthesis equipment to work within the aims of this related project.
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