Cammers' Group Research Interests
We study and design functional molecular recognition on the basis of "predictable" conformational preferences in water. The primary design parameters in the control of conformation and function are hydrophobic, hydrogen bonding and coulombic interactions. We are interested in how competitive solvation affects these parameters. The following outlines some research areas under current exploration. The research is drawing our attention toward the particularities of aqueous solvation.
Water Soluble Organic Molecules for the Molecular Recognition of Oxo-anions
Water is the most competitive solvent in its solvation of anions. The selective extraction of anions from aqueous media by organic molecules presents the organic chemist with a hardy challenge. Cations are usually discriminated on the basis of charge and size. A hypothetical molecular process which discriminates between similar multiatomic anions in aqueous solution has more demands placed upon it. In general, anions of interest are more charge-diffuse and topologically more complex than the corresponding heavy metal cations with which water quality specialists concern themselves. Topological complexity and varied physical properties should enable the design of molecular systems to selectively recognize anions. The main obstacle to this hypothesis is the competitive stabilizing interaction established between water and these anions.
We seek schemes to sequester hydrophilic moieties from aqueous solution. This concept has gone nanometric.ref-link]
Polypeptoid Design and Protein Folding
Due to cooperative contributions, proteins display two-state behavior: the folded native state and a random coil state. We aim to harness the factors that spawn cooperativity in the design of minimalist peptide-like sequences. While the mechanisms of protein folding and predictability from primary structure are still mysterious, nature has afforded us a few clues from which to work. There are over 400 protein structures known by X-ray diffraction. From solution and solid state morphology and denaturation studies we know proteins pay a high price for charge burial. Reverse turns, hairpins and loops are places about which polypeptide structures separate domains in proteins. Increased frequency of hydrophobic residues about b-sheets implies that these have hydrophobic faces. Helices can pack with enough energy to drive dimerization. Furthermore, domains excised from native conformations of proteins that are spatially related, often tend to dimerize in solution.[[ref-link]
Condensed Phase p-Stacking
Aromatic interaction is often cited in the conformational control of biological molecules. Studies have pointed to favorable electrostatic (dipole and quadrupole) interactions between aromatic surfaces giving rise to cohesive forces, so there is nothing special about p-stacking. Work remains to be done to enrich human understanding of p-stacking in order to use it more effectively as a molecular design tool and to properly conceptualize it. We have devised a model for water-soluble, face-to-face, center-to-edge (FFCE) p-stacking. Our studies favor the argument that p-stacking is a cohesive aspect of organic molecules that entirely relies on electrostatics.[ref-link] NSF.
CAMMERS RESEARCH GROUP at the UNIVERSITY of KENTUCKY
We study and design molecular recognition
the choreography that quickens