W0431

Motion of the Active Site Loop of TIM: Connection to Chemistry? Ann McDermott, Sharon Rozovsky, Dept. of Chemistry, Columbia Univ., 3000 Broadway, New York, NY 10027 USA.

The active site loop of Triose phosphate Isomerase carries out a crucial motion for enzymatic catalysis, alternating between open and closed (catalytic) conformations. Several biophysical methods give good agreement in determinations of the rates of opening and closing. These rates depend on the ligand present in the active site as will be discussed. Recent structural spectroscopic and computational efforts also offer insights into the mechanism of this enzyme, which will be summarized.