Research Program–
Structure-Function Relationships in Proteins

Correlating the structure of a given polypeptide with its biological activity is a central theme in biochemistry.  Within the Keck Center, a vigorous program has been established to ascertain the effects of polypeptide structure on activity, with emphasis on proteins related to hemostasis/fibrinolysis and peptides that modulate NMDA receptor ion flow.  Elaboration of the sequence determinants and structural features that control functionality in these systems not only expands our understanding of basic precepts in structural biology, but has far-reaching implications for the development of therapeutic interventions for pathologies associated with protein dysfunction.

The first step in dissecting structure-function relationships is to generate, in quantity, the peptide or protein target.  In our center, we have honed an array of methodologies in peptide synthesis and protein expression, as well as in the purification and characterization of all polypeptides produced.  This permits us to maintain a constant pipeline of normal and mutant molecules for study.  With the purified target in hand, detailed biochemical, biophysical and functional analyses are aided by a state-of-the-art instrumental infrastructure.  Commonly employed techniques include two-dimensional NMR spectroscopy, X-ray crystallography, microcalorimetry, analytical ultracentrifugation, surface plasmon resonance, fluorimetry, circular dichroism spectroscopy, electrophysiology, and radioligand binding.  With this capacity for extensive characterization, we can deconstruct the molecular features of a polypeptide that govern its optimal functioning in the physiological context.   The results of these in vitro analyses are frequently used as a springboard for further studies involving gene-deletion in whole animals.  This permits us to examine the roles, in vivo, of selected proteins and protein domains.

Research Program Investigators

Recent Publications

Sheng Z, Prorok M, Brown BE, Castellino FJ.  (2008).  N-methyl-d-aspartate receptor inhibition by anapolipoprotein E-derived peptide relies on low-density lipoprotein receptor-associated protein.  Neuropoharmacology 55:204-214.

Cnudde SE, Prorok M, Dai Q, Castellino FJ, Geiger JH.  (2007).  The crystal structures of the calcium-bound con-G and con-T[K7gamma] dimeric peptides demonstrate a metal-dependent helix-forming motif.  J. Am. Chem. Soc. 129:1586-1593.

Sheng Z Dai Q, Prorok M, Castellino FJ.  (2007).  Subtype-selective antagonism of N-methyl-D-aspartate receptor ion channels by synthetic conatokin peptides.  Neuropharmacology.  53:145-156.