Can an external electric field switch between ethylene formation and <scp>l</scp>-arginine hydroxylation in the ethylene forming enzyme?
Shobhit S. Chaturvedi, Simahudeen Bathir Jaber Sathik Rifayee, Rajeev Ramanan, Joel A. Rankin, Jian Hu, Robert P. Hausinger, Christo Christov
Abstract
˙·2OG·L-Arg complex can switch the EFE reactivity between L-Arg hydroxylation and ethylene generation. Furthermore, we explored how applying an ExtEF alters the geometry, electronic structure of the key reaction intermediates, and the individual energy contributions of second coordination sphere (SCS) residues through combined quantum mechanics/molecular mechanics (QM/MM) calculations. Experimentally generated variant forms of EFE with alanine substituted for SCS residues responsible for stabilizing the key intermediates in the two reactions of EFE led to changes in enzyme activity, thus demonstrating the key role of these residues. Overall, the results of applying an ExtEF indicate that making the IntEF of EFE less negative and stabilizing the off-line binding of 2OG is predicted to increase ethylene generation while reducing L-Arg hydroxylation.