Dr. Yanli Wang
Department of Chemistry
The University of Toledo
Toledo, OH

Informal

Wednesday, May 7, 2003
10:00 am (CT)
3269 Beckman Institute

Abstract

Carotenoids play the dual function of light-havesting and photo-protection. Despite their vital function, little is known about the molecular basis of binding carotenoids in photosynthetic proteins. We have analyzed all known crystal structures of pigment-protein complexes and discovered that all carotenoids are surrounded by either aromatic residues or chlorophylls. Subsequent quantum chemical calculations at the MP2/6-31G* level of theory led to the conclusion that pi-pi stacking interactions between carotenoids and their surrounding aromatic groups are responsible for binding carotenoids in the pigment proteins. Recently, we have carried out a large scale data mining and quantum chemical analysis of the Protein Data Bank (PDB) in order to decipher the molecular determinants for recognition of ATP in ATP-binding proteins. In addition to confirming the importance of the widely known hydrogen bonding, we discovered that two additional forms of intermolecular interactions, i.e., pi-pi stacking and cation- pi interactions, are crucial for ATP binding in proteins.