Exploring Reactive Conformations of Coenzyme A during Binding and Unbinding to Pyruvate Formate-Lyase.

Pyruvate formate-lyase (PFL) is a glycyl radical enzyme that converts pyruvate and coenzyme A (CoA) into formate and acetyl-CoA in two half-reactions. Recently, we showed that the acetylation of the PFL active site in the first half-reaction induces subtle conformational changes, leading to the opening of a potential channel for CoA entry. Entry of CoA into the active site is crucial for the second half-reaction, involving the acetyl transfer to CoA, and the completion of the catalytic cycle.

The Influence of Chemical Change on Protein Dynamics: A Case Study with Pyruvate Formate-Lyase.

Pyruvate formate-lyase (PFL) catalyzes the reversible conversion of pyruvate and coenzyme A (CoA) into formate and acetyl-CoA in two half-reactions. For the second half-reaction to take place, the S-H group of CoA must enter the active site of the enzyme to retrieve a protein-bound acetyl group. However, CoA is bound at the protein surface, whereas the active site is buried in the protein interior, some 20-30 Å away.

Conductivity dispersion in supercooled calcium potassium nitrate: caged ionic motion viewed as part of standard behaviour.

Conductivity spectra of ionic materials with disordered structures are usually thought to consist of several parts, i.e., the DC conductivity, a power-law component, a nearly-constant-loss feature (if identified) and the (far-)infrared conductivity caused by vibrational motion.